Hi codeforces! I was deleting the element from ordered map but when i delete the last element from map then i got the RE! why? :(
code
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Hi codeforces! I was deleting the element from ordered map but when i delete the last element from map then i got the RE! why? :(
#include<bits/stdc++.h>
using namespace std;
void solve(){
int n;
cin>>n;
map<int,int>a;
for(int i=1;i<=n;i++){
int x; cin>>x;
a[i]=x;
}
map<int,int>::iterator it=a.begin();
a.erase(it);
// a.erase(it);
// if i uncomment the upper line then i got RE because iam deleting the last element :(
/* input
2
1 2
iam considering that my ordered map have only 2 elements.
*/
}
int main(){
solve();
}
Name |
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iterators don't work that way
if you erase like in the code, then
it
will be invalidated, or you can say it "doesn't work" anymoreyou can just call
a.erase(a.begin())
twice