oj.uz

Submission #489607

# Submission time Handle Problem Language Result Execution time Memory
489607 2021-11-23T10:57:00 Z pliam Election (BOI18_election) C++14
100 / 100
 458 ms 28340 KB 
#include <bits/stdc++.h>
#define MAXN 500000
using namespace std;

int N,Q,a[MAXN];
struct node{
    int pref,suff,sum,ans;
};

node st[4*MAXN];

node merge(node nl,node nr){
    node n;
    n.pref=max(nl.pref,nl.sum+nr.pref);
    n.suff=max(nr.suff,nr.sum+nl.suff);
    n.sum=nl.sum+nr.sum;
    n.ans=max({nl.pref+nr.suff,nl.sum+nr.ans,nr.sum+nl.ans});
    return n;
}

//segment tree
void build(int v=1,int start=0,int end=N-1){
    if(start==end){
        st[v]={max(0,a[start]),max(0,a[start]),a[start],max(0,a[start])};
        return;
    }
    int mid=(start+end)/2;
    build(2*v,start,mid);
    build(2*v+1,mid+1,end);
    st[v]=merge(st[2*v],st[2*v+1]);
}

node query(int from,int to,int v=1,int start=0,int end=N-1){
    if(start==from&&end==to){
        return st[v];
    }
    int mid=(start+end)/2;
    if(to<=mid){
        return query(from,to,2*v,start,mid);
    }else if(from>mid){
        return query(from,to,2*v+1,mid+1,end);
    }else{
        return merge(query(from,mid,2*v,start,mid),query(mid+1,to,2*v+1,mid+1,end));
    }
}

int main(){
    scanf("%d",&N);
    for(int i=0;i<N;i++){
        char c;
        scanf(" %c",&c);
        a[i]=(c=='C')?-1:1;
    }
    build();
    scanf("%d",&Q);
    for(int i=0;i<Q;i++){
        int l,r;
        scanf("%d %d",&l,&r);
        l--; r--;
        printf("%d\n",query(l,r).ans);
    }
}

Compilation message

election.cpp: In function 'int main()':
election.cpp:48:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |     scanf("%d",&N);
      |     ~~~~~^~~~~~~~~
election.cpp:51:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   51 |         scanf(" %c",&c);
      |         ~~~~~^~~~~~~~~~
election.cpp:55:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   55 |     scanf("%d",&Q);
      |     ~~~~~^~~~~~~~~
election.cpp:58:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   58 |         scanf("%d %d",&l,&r);
      |         ~~~~~^~~~~~~~~~~~~~~

Subtask #1
28.0 / 28.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 332 KB Output is correct
5 Correct 2 ms 332 KB Output is correct

Subtask #2
54.0 / 54.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 332 KB Output is correct
5 Correct 2 ms 332 KB Output is correct
6 Correct 47 ms 4848 KB Output is correct
7 Correct 46 ms 5744 KB Output is correct
8 Correct 45 ms 5792 KB Output is correct
9 Correct 41 ms 5804 KB Output is correct
10 Correct 46 ms 5744 KB Output is correct
11 Correct 47 ms 5904 KB Output is correct
12 Correct 47 ms 5884 KB Output is correct
13 Correct 48 ms 5956 KB Output is correct
14 Correct 54 ms 5876 KB Output is correct
15 Correct 64 ms 5772 KB Output is correct

Subtask #3
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 332 KB Output is correct
5 Correct 2 ms 332 KB Output is correct
6 Correct 47 ms 4848 KB Output is correct
7 Correct 46 ms 5744 KB Output is correct
8 Correct 45 ms 5792 KB Output is correct
9 Correct 41 ms 5804 KB Output is correct
10 Correct 46 ms 5744 KB Output is correct
11 Correct 47 ms 5904 KB Output is correct
12 Correct 47 ms 5884 KB Output is correct
13 Correct 48 ms 5956 KB Output is correct
14 Correct 54 ms 5876 KB Output is correct
15 Correct 64 ms 5772 KB Output is correct
16 Correct 432 ms 27336 KB Output is correct
17 Correct 379 ms 27460 KB Output is correct
18 Correct 423 ms 27388 KB Output is correct
19 Correct 341 ms 26964 KB Output is correct
20 Correct 445 ms 26524 KB Output is correct
21 Correct 435 ms 28260 KB Output is correct
22 Correct 449 ms 28184 KB Output is correct
23 Correct 458 ms 28340 KB Output is correct
24 Correct 429 ms 28004 KB Output is correct
25 Correct 438 ms 27464 KB Output is correct