Help Needed: Codeforces Round 973 (Div. 2) D. Minimize the Difference

problem.

Hi everyone,
I’ve been trying to solve problem D: Minimize the Difference from Codeforces Round 973 (Div. 2). I’ve spent quite a bit of time debugging my code, but I can’t figure out why it’s not working as expected. :(

Here’s what I tried to do:
I sorted the input intervals by their start times.

I used a priority queue to keep track of the active intervals within the current window.

As I slide the window from d to n, I:

-Remove intervals that are no longer in the range.

-Add new intervals that fall within the range.

I kept track of the window with the maximum and minimum number of intervals by checking the size of the priority queue.

However, it's giving WA on testcase 2.

Code:

#include <bits/stdc++.h>
using namespace std;

#define sp " "
#define newline cout << "\n"
#define yes cout << "YES"
#define no cout << "NO"
#define int long long
#define yesif(flag) cout << ((flag) ? "YES" : "NO")
#define all(a)  a.begin(), a.end()
#define pb(a) push_back(a)

typedef long long       ll;
typedef pair<int, int>  pii;
typedef pair<ll, ll>    pll;
typedef vector<int>     vi;
typedef vector<ll>      vll;
typedef vector<pii>     vpii;
typedef vector<pll>     vpll;
typedef map<int, int>   mii;
typedef map<ll, ll>     mll;
typedef set<int>        si;
typedef set<ll>         sl;

template<typename T> void sort_unique(vector<T> &vec){sort(vec.begin(),vec.end()); vec.resize(unique(vec.begin(),vec.end())-vec.begin());}
template<typename T> void scan(vector<T> &v){for(auto &i :v) cin >> i;}
template<typename T> void print(vector<T> &v){for(auto &i :v) cout << i << " ";}

#ifdef LOCAL
#include "debug.h"
#else
#define bug(...) 
#endif

void print(priority_queue<pair<int,int>,vector<pair<int, int>>, greater<pair<int, int>>> pq){
    while(pq.empty() == false) {
        cout << pq.top().first << " " << pq.top().second << endl; pq.pop();
    }
}
void tTestCase() {
    int t;
    cin >> t;
    while (t--) {
        int n, d, k;
        cin >> n >> d >> k;
        vpii points;
        for (int i = 0; i < k; ++i) {
            int a, b; cin >> a >> b;
            points.push_back({a, b});
        }   
        sort(all(points));

        bug(points);
        priority_queue<pair<int,int>,vector<pair<int, int>>, greater<pair<int, int>>> pq;
        int indx = 0, res1 = 0, res2 = 0, temp1 = 0, temp2 = INT_MAX ;

        for (int i = d; i <= n; ++i){
            
            while(pq.empty() == false and pq.top().second < (i - d + 1)){
                // if(!pq.empty())
                  pq.pop();
            }

            while(indx < k and   points[indx].first <= i and points[indx].second >= (i - d + 1)) {
                   pq.push(points[indx]);
                indx++;
            }   

            int sz = pq.size();
            bug(sz);
            if(sz > temp1) {
                temp1 = sz;
                res1 = i - d + 1;
            }
            if(sz < temp2) {
                temp2 = sz;
                res2 = i - d + 1;
            }

        }
        cout << res1 << " " << res2;

        newline;
    }
}

void solve() { 
    tTestCase(); 
}

int32_t main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    solve();

    return 0;
}

If anyone could kindly review my code and point out what I’m doing wrong, I’d be immensely grateful! :)

Any feedback or suggestions to improve the implementation or debug this further would mean a lot. Thank you so much in advance for your time and help! ^ ^