Submission #467926

#	Time	Username	Problem	Language	Result	Execution time	Memory
467926		MilosMilutinovic	Sum Zero (RMI20_sumzero)	C++14	0 / 100	3 ms	672 KiB

sumzero

#include <bits/stdc++.h>
using namespace std;
#define ll long long
const int N=400005;
const int L=18;
int a[N];
int st[L][N];
void Build(int n){
    for(int i=0;i<N;i++){
        for(int j=0;j<L;j++)st[i][j]=N-2;
    }
    map<ll,int> was;
    ll sum=0;
    was[0]=0;
    for(int i=1;i<=n;i++){
        sum+=a[i];
        if(was.count(sum)){
            st[was[sum]+1][0]=i;
        }
        was[sum]=i;
    }
    int mn=N-1;
    for(int i=n;i>=1;i--)st[i][0]=min(st[i+1][0],st[i][0]);
    for(int i=1;i<L;i++){
        for(int j=1;j<=n;j++){
            st[j][i]=st[st[j][i-1]+1][i-1];
        }
    }
}
int main(){
    int n;scanf("%i",&n);
    for(int i=1;i<=n;i++)scanf("%i",&a[i]);
    Build(n);
    int q;scanf("%i",&q);
    int l,r,ans=0;
    while(q--){
        scanf("%i%i",&l,&r);
        ans=0;
        for(int i=L-1;i>=0;i--){
            if(st[l][i]<=r)ans+=(1<<i),l=st[l][i]+1;
        }
        printf("%i\n",ans);
    }
    return 0;
}

Compilation message (stderr)

sumzero.cpp: In function 'void Build(int)':
sumzero.cpp:22:9: warning: unused variable 'mn' [-Wunused-variable]
   22 |     int mn=N-1;
      |         ^~
sumzero.cpp: In function 'int main()':
sumzero.cpp:31:16: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |     int n;scanf("%i",&n);
      |           ~~~~~^~~~~~~~~
sumzero.cpp:32:31: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 |     for(int i=1;i<=n;i++)scanf("%i",&a[i]);
      |                          ~~~~~^~~~~~~~~~~~
sumzero.cpp:34:16: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |     int q;scanf("%i",&q);
      |           ~~~~~^~~~~~~~~
sumzero.cpp:37:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |         scanf("%i%i",&l,&r);
      |         ~~~~~^~~~~~~~~~~~~~
sumzero.cpp: In function 'void Build(int)':
sumzero.cpp:10:37: warning: iteration 18 invokes undefined behavior [-Waggressive-loop-optimizations]
   10 |         for(int j=0;j<L;j++)st[i][j]=N-2;
      |                             ~~~~~~~~^~~~
sumzero.cpp:9:18: note: within this loop
    9 |     for(int i=0;i<N;i++){
      |                 ~^~

• Subtask 1: 0 / 22
• Subtask 2: 0 / 39
• Subtask 3: 0 / 39