_This time_, [user:Auroraa_,2024-05-10] is solving [problem:524E]. After some trial, he got ↵
↵
<spoiler summary="this code">↵
↵
~~~~~↵
// Code written by Auroraa_↵
#include "bits/stdc++.h"↵
↵
using namespace std;↵
#define endl '\n'↵
↵
const int N = 2e5 + 5;↵
↵
#define ls (p<<1)↵
#define rs ((p<<1)|1)↵
#define mid ((l+r)>>1)↵
↵
struct Seg {↵
int l, r;↵
int mn;↵
}seg[4 * N];↵
void build(int p, int l, int r) {↵
seg[p].l = l, seg[p].r = r;↵
seg[p].mn = 0;↵
if (l == r)return;↵
build(ls, l, mid);↵
build(rs, mid + 1, r);↵
}↵
void upd(int p, int x, int y) {↵
int l = seg[p].l, r = seg[p].r;↵
if (l == r) {↵
seg[p].mn = y;↵
return;↵
}↵
if (x <= mid)upd(ls, x, y);↵
else upd(rs, x, y);↵
seg[p].mn = min(seg[ls].mn, seg[rs].mn);↵
}↵
int ask(int p, int x, int y) {↵
int l = seg[p].l, r = seg[p].r;↵
if (x <= l && y >= r)return seg[p].mn;↵
int ans = 1000000;↵
if (x <= mid)ans = min(ans, ask(ls, x, y));↵
if (y > mid)ans = min(ans, ask(rs, x, y));↵
return ans;↵
}↵
int ans[N];↵
struct query {↵
int x1, y1, x2, y2, id;↵
};↵
bool cmp_x(query q1, query q2) { return q1.x2 < q2.x2; }↵
bool cmp_y(query q1, query q2) { return q1.y2 < q2.y2; }↵
vector<query>vec;↵
vector<int>v1[N], v2[N];↵
void solve() {↵
int n, m, k, q;↵
cin >> n >> m >> k >> q;↵
for (int i = 1; i <= k; i++) {↵
int x, y;↵
cin >> x >> y;↵
v1[x].push_back(y);↵
v2[y].push_back(x);↵
}↵
↵
for (int i = 1; i <= q; i++) {↵
int x1, y1, x2, y2;↵
cin >> x1 >> y1 >> x2 >> y2;↵
vec.push_back({ x1, y1, x2, y2, i });↵
}↵
↵
sort(vec.begin(), vec.end(), cmp_y);↵
↵
↵
build(1, 1, n);↵
int now = 0;↵
for (int i = 1; i <= m; i++) {↵
for (auto x : v2[i])upd(1, x, i);↵
while (now < q && vec[now].y2 <= i) {↵
if (ans[vec[now].id] == 1) {↵
now++;↵
continue;↵
}↵
int mn = ask(1, vec[now].x1, vec[now].x2);↵
if (vec[now].y1 <= mn)ans[vec[now].id] = 1;↵
now++;↵
}↵
if (now == q)break;↵
}↵
↵
build(1, 1, m);↵
sort(vec.begin(), vec.end(), cmp_x);↵
now = 0;↵
↵
for (int i = 1; i <= n; i++) {↵
for (auto y : v1[i]) {↵
upd(1, y, i);↵
}↵
while (now < q && vec[now].x2 <= i) {↵
if (ans[vec[now].id] == 1) {↵
now++;↵
continue;↵
}↵
int mn = ask(1, vec[now].y1, vec[now].y2);↵
if (vec[now].x1 <= mn)ans[vec[now].id] = 1;↵
now++;↵
}↵
if (now == q)break;↵
}↵
↵
for (int i = 1; i <= q; i++) {↵
if (ans[i] == 0)cout << "NO" << endl;↵
else cout << "YES" << endl;↵
}↵
↵
}↵
↵
signed main() {↵
cin.tie(nullptr)->sync_with_stdio(false);↵
int T = 1;↵
// cin>>T;↵
while (T--) {↵
solve();↵
}↵
}↵
~~~~~↵
↵
</spoiler>↵
↵
and then received TLE: [submission:260160406]↵
↵
He was surprised, so he tried it again with exact same code, with C++17 (32). You know what? The AC magic happened [again](https://codeforces.me/blog/entry/126573#:~:text=with%20different%20language.-,You%20know%20what,-%3F): [submission:260161644].↵
↵
At first glance, we do think some code has triggered [undefined behaviours](https://en.cppreference.com/w/cpp/language/ub#:~:text=program%20that%20does-,not,-fall%20into%20one) like Access out of bounds. But [user:Auroraa_,2024-05-10] denied that, because all the data could be fit in [int32_t](https://en.cppreference.com/w/cpp/header/cstdint).↵
↵
Then came the dramatic scene: by simply changing the code `vector<int>v1[N], v2[N];` to `vector<long long>v1[N], v2[N];`, the strange TLE problem disappeared: [submission:260164936].↵
↵
After that, my further investigation([submission:260199113]) pointed out that the block causes TLE is:↵
↵
~~~~~↵
for (int i = 1; i <= q; i++) {↵
int x1, y1, x2, y2;↵
cin >> x1 >> y1 >> x2 >> y2;↵
vec.push_back({ x1, y1, x2, y2, i });↵
}↵
~~~~~↵
↵
It took over 2000ms([submission:260199205]) to write data into **this** vec. And only took about 100ms([submission:260199447]) to do the same thing if we just changed `vector<int>v1[N], v2[N];` to `vector<long long>v1[N], v2[N];`. The weirdest thing is, there is no direct connection between v1,v2 and vec.↵
↵
-----↵
↵
Recalling the process just described, coincidentally, this modification process is really similar to the blog [_Strange TLE by cin using GNU C++20 (64), and some weird subtle changes to (surprisingly) fix it_](https://codeforces.me/blog/entry/126573).↵
↵
And like this blog [_Slowdown bug affecting C++ (64 bit) on Codeforces_](https://codeforces.me/blog/entry/126654), this time we encountered a Pandora's Box that just used a different magic number to open. Although [user:MikeMirzayanov,2024-05-10] has updated the CF system to ↵
↵
<spoiler summary="Windows Server 2022">↵
~~~~~↵
#include <iostream>↵
#include <string>↵
#include <cinttypes>↵
#include "Windows.h"↵
#include "VersionHelpers.h"↵
#include "cpuid.h"↵
↵
//https://zhuanlan.zhihu.com/p/28322626↵
void getCPUID() {↵
uint32_t data[4];↵
char str[48];↵
for (int i = 0; i < 3; ++i) {↵
__cpuid_count(0x80000002 + i, 0, data[0], data[1], data[2], data[3]);↵
for (int j = 0; j < 4; ++j)↵
reinterpret_cast<uint32_t*>(str)[i * 4 + j] = data[j];↵
}↵
std::cout << str << std::endl;↵
}↵
↵
//https://www.cnblogs.com/LyShark/articles/15019661.html↵
//https://bbs.kanxue.com/thread-252559.htm↵
void getSysVersion() {↵
std::string ret = std::string(IsWindowsServer() ? "Windows Server" : "Windows") + " ";↵
typedef void(__stdcall * NTPROC)(DWORD*, DWORD*, DWORD*);↵
DWORD dwMajor, dwMinor, dwBuildNumber;↵
NTPROC proc = (NTPROC)GetProcAddress(↵
LoadLibrary(TEXT("ntdll.dll")),↵
"RtlGetNtVersionNumbers"↵
);↵
uintptr_t PEB;↵
proc(&dwMajor, &dwMinor, &dwBuildNumber);↵
#ifdef _WIN64↵
PEB = __readgsqword(0x60);↵
dwBuildNumber = *((INT*)(PEB + 0x120));↵
#else↵
PEB = __readfsdword(0x30);↵
dwBuildNumber = *((INT*)(PEB + 0xAC));↵
#endif↵
if (dwMajor >= 6) {↵
ret += std::to_string(dwMajor) + "." + std::to_string(dwMinor) + "." + std::to_string(dwBuildNumber);↵
}↵
else {↵
// win 8↵
float f_ret;↵
SYSTEM_INFO info;↵
GetSystemInfo(&info);↵
OSVERSIONINFOEX os;↵
os.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX);↵
if (GetVersionEx((OSVERSIONINFO*)&os)) {↵
f_ret = os.dwMajorVersion + os.dwMinorVersion * 0.1;↵
ret += std::to_string(f_ret);↵
}↵
}↵
std::cout << ret << std::endl;↵
}↵
↵
//https://www.cnblogs.com/lidabo/p/7554473.html↵
void getMemoryInfo() {↵
constexpr int kMaxInfoBuffer = 1 << 8;↵
constexpr int GBYTES = 1 << 30;↵
constexpr int MBYTES = 1 << 20;↵
constexpr int KBYTES = 1 << 10;↵
constexpr float DKBYTES = KBYTES;↵
std::string memory_info;↵
MEMORYSTATUSEX statusex;↵
statusex.dwLength = sizeof(statusex);↵
if (GlobalMemoryStatusEx(&statusex)) {↵
uint64_t total = 0, remain_total = 0, avl = 0, remain_avl = 0;↵
double decimal_total = 0, decimal_avl = 0;↵
remain_total = statusex.ullTotalPhys % GBYTES;↵
total = statusex.ullTotalPhys / GBYTES;↵
avl = statusex.ullAvailPhys / GBYTES;↵
remain_avl = statusex.ullAvailPhys % GBYTES;↵
if (remain_total > 0)↵
decimal_total = (remain_total / static_cast<double>(MBYTES)) / DKBYTES;↵
if (remain_avl > 0)↵
decimal_avl = (remain_avl / static_cast<double>(MBYTES)) / DKBYTES;↵
↵
decimal_total += (double)total;↵
decimal_avl += (double)avl;↵
char buffer[kMaxInfoBuffer];↵
//sprintf_s(buffer, kMaxInfoBuffer, "total %.2f GB (%.2f GB available)", decimal_total, decimal_avl);↵
std::sprintf(buffer, "total %.2f GB (%.2f GB available)", decimal_total, decimal_avl);↵
memory_info.append(buffer);↵
}↵
std::cout << memory_info << std::endl;↵
}↵
↵
int main() {↵
std::cout << "===OS information===" << std::endl;↵
getSysVersion();↵
std::cout << "===CPU information===" << std::endl;↵
getCPUID();↵
std::cout << "===Memory information===" << std::endl;↵
getMemoryInfo();↵
}↵
~~~~~↵
</spoiler>↵
↵
, there is still something fishy here.↵
↵
The new version of GCC and OS **passed** the "test" on [_You won't believe how this simple trick defeated the unexplained bug destroying every top LGM_](https://codeforces.me/blog/entry/126677); also included [other languages such as Rust](https://codeforces.me/blog/entry/127586?#comment-1133334). [The script mentioned there](https://codeforces.me/contest/1/submission/253513254) doesn't work for Rust **not** work for [Rust](https://github.com/rust-lang/rust/blob/master/library/std/src/sys/pal/windows/alloc.rs#L139) now (both in custom test and on my Windows 11 computer).↵
↵
I translate the script to C++: ↵
↵
~~~~~↵
#include "bits/stdc++.h"↵
↵
int main() {↵
constexpr size_t n = 30000;↵
auto vec = std::vector<std::vector<int>>(n);↵
for (size_t i = 10000; i < 20000; i++) {↵
vec.resize(i);↵
for (size_t j = 0; j < i; j++) {↵
vec[j].reserve(7);↵
}↵
auto start = std::chrono::system_clock::now();↵
for (size_t j = 0; j < 10000; j++) {↵
vec[i - 1].reserve(7);↵
vec[i - 1].shrink_to_fit();↵
}↵
auto elapsed = std::chrono::duration<double, std::milli>(std::chrono::system_clock::now() - start).count();↵
if (elapsed > 40) {↵
std::cout << i << " " << elapsed << "\n";↵
}↵
}↵
}↵
~~~~~↵
↵
and also [the bomb](https://codeforces.me/contest/1/submission/253512897):↵
↵
~~~~~↵
#include "bits/stdc++.h"↵
↵
int main() {↵
constexpr size_t n = 30000;↵
constexpr size_t evil = 17182;↵
auto vec = std::vector<std::vector<int>>(n);↵
vec.resize(evil);↵
for (size_t i = 0; i < evil; i++) {↵
vec[i].reserve(7);↵
}↵
for (size_t i = 0; i < size_t(1e6); i++) {↵
vec[evil - 1].reserve(7);↵
vec[evil - 1].shrink_to_fit();↵
}↵
}↵
~~~~~↵
And it generated the output `Used: 5514 ms, 0 KB`↵
↵
[As usual](https://codeforces.me/contest/1/submission/253512922), I change `constexpr size_t evil = 17182;` to `constexpr size_t evil = 17183;`, and then `Used: 93 ms, 0 KB`↵
↵
OOPS, [user:MikeMirzayanov,2024-05-10]! Did you forget to upgrade compilers after migrating the CF system to Windows Server 2022?↵
If that's true, please, upgrade those compilers to **UCRT** version, andyou canI suggest you could simply use [the one with LLVM](https://github.com/brechtsanders/winlibs_mingw/releases/download/14.1.0posix-18.1.5-11.0.1-ucrt-r1/winlibs-x86_64-posix-seh-gcc-14.1.0-llvm-18.1.5-mingw-w64ucrt-11.0.1-r1.7z) for the simplest configuration for clang18 with GCC's libstdc++.
↵
<spoiler summary="this code">↵
↵
~~~~~↵
// Code written by Auroraa_↵
#include "bits/stdc++.h"↵
↵
using namespace std;↵
#define endl '\n'↵
↵
const int N = 2e5 + 5;↵
↵
#define ls (p<<1)↵
#define rs ((p<<1)|1)↵
#define mid ((l+r)>>1)↵
↵
struct Seg {↵
int l, r;↵
int mn;↵
}seg[4 * N];↵
void build(int p, int l, int r) {↵
seg[p].l = l, seg[p].r = r;↵
seg[p].mn = 0;↵
if (l == r)return;↵
build(ls, l, mid);↵
build(rs, mid + 1, r);↵
}↵
void upd(int p, int x, int y) {↵
int l = seg[p].l, r = seg[p].r;↵
if (l == r) {↵
seg[p].mn = y;↵
return;↵
}↵
if (x <= mid)upd(ls, x, y);↵
else upd(rs, x, y);↵
seg[p].mn = min(seg[ls].mn, seg[rs].mn);↵
}↵
int ask(int p, int x, int y) {↵
int l = seg[p].l, r = seg[p].r;↵
if (x <= l && y >= r)return seg[p].mn;↵
int ans = 1000000;↵
if (x <= mid)ans = min(ans, ask(ls, x, y));↵
if (y > mid)ans = min(ans, ask(rs, x, y));↵
return ans;↵
}↵
int ans[N];↵
struct query {↵
int x1, y1, x2, y2, id;↵
};↵
bool cmp_x(query q1, query q2) { return q1.x2 < q2.x2; }↵
bool cmp_y(query q1, query q2) { return q1.y2 < q2.y2; }↵
vector<query>vec;↵
vector<int>v1[N], v2[N];↵
void solve() {↵
int n, m, k, q;↵
cin >> n >> m >> k >> q;↵
for (int i = 1; i <= k; i++) {↵
int x, y;↵
cin >> x >> y;↵
v1[x].push_back(y);↵
v2[y].push_back(x);↵
}↵
↵
for (int i = 1; i <= q; i++) {↵
int x1, y1, x2, y2;↵
cin >> x1 >> y1 >> x2 >> y2;↵
vec.push_back({ x1, y1, x2, y2, i });↵
}↵
↵
sort(vec.begin(), vec.end(), cmp_y);↵
↵
↵
build(1, 1, n);↵
int now = 0;↵
for (int i = 1; i <= m; i++) {↵
for (auto x : v2[i])upd(1, x, i);↵
while (now < q && vec[now].y2 <= i) {↵
if (ans[vec[now].id] == 1) {↵
now++;↵
continue;↵
}↵
int mn = ask(1, vec[now].x1, vec[now].x2);↵
if (vec[now].y1 <= mn)ans[vec[now].id] = 1;↵
now++;↵
}↵
if (now == q)break;↵
}↵
↵
build(1, 1, m);↵
sort(vec.begin(), vec.end(), cmp_x);↵
now = 0;↵
↵
for (int i = 1; i <= n; i++) {↵
for (auto y : v1[i]) {↵
upd(1, y, i);↵
}↵
while (now < q && vec[now].x2 <= i) {↵
if (ans[vec[now].id] == 1) {↵
now++;↵
continue;↵
}↵
int mn = ask(1, vec[now].y1, vec[now].y2);↵
if (vec[now].x1 <= mn)ans[vec[now].id] = 1;↵
now++;↵
}↵
if (now == q)break;↵
}↵
↵
for (int i = 1; i <= q; i++) {↵
if (ans[i] == 0)cout << "NO" << endl;↵
else cout << "YES" << endl;↵
}↵
↵
}↵
↵
signed main() {↵
cin.tie(nullptr)->sync_with_stdio(false);↵
int T = 1;↵
// cin>>T;↵
while (T--) {↵
solve();↵
}↵
}↵
~~~~~↵
↵
</spoiler>↵
↵
and then received TLE: [submission:260160406]↵
↵
He was surprised, so he tried it again with exact same code, with C++17 (32). You know what? The AC magic happened [again](https://codeforces.me/blog/entry/126573#:~:text=with%20different%20language.-,You%20know%20what,-%3F): [submission:260161644].↵
↵
At first glance, we do think some code has triggered [undefined behaviours](https://en.cppreference.com/w/cpp/language/ub#:~:text=program%20that%20does-,not,-fall%20into%20one) like Access out of bounds. But [user:Auroraa_,2024-05-10] denied that, because all the data could be fit in [int32_t](https://en.cppreference.com/w/cpp/header/cstdint).↵
↵
Then came the dramatic scene: by simply changing the code `vector<int>v1[N], v2[N];` to `vector<long long>v1[N], v2[N];`, the strange TLE problem disappeared: [submission:260164936].↵
↵
After that, my further investigation([submission:260199113]) pointed out that the block causes TLE is:↵
↵
~~~~~↵
for (int i = 1; i <= q; i++) {↵
int x1, y1, x2, y2;↵
cin >> x1 >> y1 >> x2 >> y2;↵
vec.push_back({ x1, y1, x2, y2, i });↵
}↵
~~~~~↵
↵
It took over 2000ms([submission:260199205]) to write data into **this** vec. And only took about 100ms([submission:260199447]) to do the same thing if we just changed `vector<int>v1[N], v2[N];` to `vector<long long>v1[N], v2[N];`. The weirdest thing is, there is no direct connection between v1,v2 and vec.↵
↵
-----↵
↵
Recalling the process just described, coincidentally, this modification process is really similar to the blog [_Strange TLE by cin using GNU C++20 (64), and some weird subtle changes to (surprisingly) fix it_](https://codeforces.me/blog/entry/126573).↵
↵
And like this blog [_Slowdown bug affecting C++ (64 bit) on Codeforces_](https://codeforces.me/blog/entry/126654), this time we encountered a Pandora's Box that just used a different magic number to open. Although [user:MikeMirzayanov,2024-05-10] has updated the CF system to ↵
↵
<spoiler summary="Windows Server 2022">↵
~~~~~↵
#include <iostream>↵
#include <string>↵
#include <cinttypes>↵
#include "Windows.h"↵
#include "VersionHelpers.h"↵
#include "cpuid.h"↵
↵
//https://zhuanlan.zhihu.com/p/28322626↵
void getCPUID() {↵
uint32_t data[4];↵
char str[48];↵
for (int i = 0; i < 3; ++i) {↵
__cpuid_count(0x80000002 + i, 0, data[0], data[1], data[2], data[3]);↵
for (int j = 0; j < 4; ++j)↵
reinterpret_cast<uint32_t*>(str)[i * 4 + j] = data[j];↵
}↵
std::cout << str << std::endl;↵
}↵
↵
//https://www.cnblogs.com/LyShark/articles/15019661.html↵
//https://bbs.kanxue.com/thread-252559.htm↵
void getSysVersion() {↵
std::string ret = std::string(IsWindowsServer() ? "Windows Server" : "Windows") + " ";↵
typedef void(__stdcall * NTPROC)(DWORD*, DWORD*, DWORD*);↵
DWORD dwMajor, dwMinor, dwBuildNumber;↵
NTPROC proc = (NTPROC)GetProcAddress(↵
LoadLibrary(TEXT("ntdll.dll")),↵
"RtlGetNtVersionNumbers"↵
);↵
uintptr_t PEB;↵
proc(&dwMajor, &dwMinor, &dwBuildNumber);↵
#ifdef _WIN64↵
PEB = __readgsqword(0x60);↵
dwBuildNumber = *((INT*)(PEB + 0x120));↵
#else↵
PEB = __readfsdword(0x30);↵
dwBuildNumber = *((INT*)(PEB + 0xAC));↵
#endif↵
if (dwMajor >= 6) {↵
ret += std::to_string(dwMajor) + "." + std::to_string(dwMinor) + "." + std::to_string(dwBuildNumber);↵
}↵
else {↵
// win 8↵
float f_ret;↵
SYSTEM_INFO info;↵
GetSystemInfo(&info);↵
OSVERSIONINFOEX os;↵
os.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX);↵
if (GetVersionEx((OSVERSIONINFO*)&os)) {↵
f_ret = os.dwMajorVersion + os.dwMinorVersion * 0.1;↵
ret += std::to_string(f_ret);↵
}↵
}↵
std::cout << ret << std::endl;↵
}↵
↵
//https://www.cnblogs.com/lidabo/p/7554473.html↵
void getMemoryInfo() {↵
constexpr int kMaxInfoBuffer = 1 << 8;↵
constexpr int GBYTES = 1 << 30;↵
constexpr int MBYTES = 1 << 20;↵
constexpr int KBYTES = 1 << 10;↵
constexpr float DKBYTES = KBYTES;↵
std::string memory_info;↵
MEMORYSTATUSEX statusex;↵
statusex.dwLength = sizeof(statusex);↵
if (GlobalMemoryStatusEx(&statusex)) {↵
uint64_t total = 0, remain_total = 0, avl = 0, remain_avl = 0;↵
double decimal_total = 0, decimal_avl = 0;↵
remain_total = statusex.ullTotalPhys % GBYTES;↵
total = statusex.ullTotalPhys / GBYTES;↵
avl = statusex.ullAvailPhys / GBYTES;↵
remain_avl = statusex.ullAvailPhys % GBYTES;↵
if (remain_total > 0)↵
decimal_total = (remain_total / static_cast<double>(MBYTES)) / DKBYTES;↵
if (remain_avl > 0)↵
decimal_avl = (remain_avl / static_cast<double>(MBYTES)) / DKBYTES;↵
↵
decimal_total += (double)total;↵
decimal_avl += (double)avl;↵
char buffer[kMaxInfoBuffer];↵
//sprintf_s(buffer, kMaxInfoBuffer, "total %.2f GB (%.2f GB available)", decimal_total, decimal_avl);↵
std::sprintf(buffer, "total %.2f GB (%.2f GB available)", decimal_total, decimal_avl);↵
memory_info.append(buffer);↵
}↵
std::cout << memory_info << std::endl;↵
}↵
↵
int main() {↵
std::cout << "===OS information===" << std::endl;↵
getSysVersion();↵
std::cout << "===CPU information===" << std::endl;↵
getCPUID();↵
std::cout << "===Memory information===" << std::endl;↵
getMemoryInfo();↵
}↵
~~~~~↵
</spoiler>↵
↵
, there is still something fishy here.↵
↵
The new version of GCC and OS **passed** the "test" on [_You won't believe how this simple trick defeated the unexplained bug destroying every top LGM_](https://codeforces.me/blog/entry/126677); also included [other languages such as Rust](https://codeforces.me/blog/entry/127586?#comment-1133334). [The script mentioned there](https://codeforces.me/contest/1/submission/253513254) does
↵
I translate the script to C++: ↵
↵
~~~~~↵
#include "bits/stdc++.h"↵
↵
int main() {↵
constexpr size_t n = 30000;↵
auto vec = std::vector<std::vector<int>>(n);↵
for (size_t i = 10000; i < 20000; i++) {↵
vec.resize(i);↵
for (size_t j = 0; j < i; j++) {↵
vec[j].reserve(7);↵
}↵
auto start = std::chrono::system_clock::now();↵
for (size_t j = 0; j < 10000; j++) {↵
vec[i - 1].reserve(7);↵
vec[i - 1].shrink_to_fit();↵
}↵
auto elapsed = std::chrono::duration<double, std::milli>(std::chrono::system_clock::now() - start).count();↵
if (elapsed > 40) {↵
std::cout << i << " " << elapsed << "\n";↵
}↵
}↵
}↵
~~~~~↵
↵
and also [the bomb](https://codeforces.me/contest/1/submission/253512897):↵
↵
~~~~~↵
#include "bits/stdc++.h"↵
↵
int main() {↵
constexpr size_t n = 30000;↵
constexpr size_t evil = 17182;↵
auto vec = std::vector<std::vector<int>>(n);↵
vec.resize(evil);↵
for (size_t i = 0; i < evil; i++) {↵
vec[i].reserve(7);↵
}↵
for (size_t i = 0; i < size_t(1e6); i++) {↵
vec[evil - 1].reserve(7);↵
vec[evil - 1].shrink_to_fit();↵
}↵
}↵
~~~~~↵
And it generated the output `Used: 5514 ms, 0 KB`↵
↵
[As usual](https://codeforces.me/contest/1/submission/253512922), I change `constexpr size_t evil = 17182;` to `constexpr size_t evil = 17183;`, and then `Used: 93 ms, 0 KB`↵
↵
OOPS, [user:MikeMirzayanov,2024-05-10]! Did you forget to upgrade compilers after migrating the CF system to Windows Server 2022?↵
If that's true, please, upgrade those compilers to **UCRT** version, and
