Submission #851251

#	Time	Username	Problem	Language	Result	Execution time	Memory
851251		askow	Bitaro the Brave (JOI19_ho_t1)	C++14	100 / 100	384 ms	159112 KiB

joi2019_ho_t1

#include <bits/stdc++.h>
#define int long long
using namespace std;
signed main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n,m;
    cin>>n>>m;
    char a[n+1][m+1];
    for(int i=1;i<=n;i++)for(int j=1;j<=m;j++)cin>>a[i][j];
    int ans=0;
    int suf[n+1][m+2];
    for(int i=0;i<=n;i++)for(int j=0;j<=m+1;j++)suf[i][j]=0;
    for(int i=1;i<=n;i++){
        for(int j=m;j>=1;j--){
            suf[i][j]=suf[i][j+1];
            if(a[i][j]=='O')suf[i][j]++;
        }
    }
    int dp[n+2][m+2];
    for(int i=0;i<=n+1;i++)for(int j=0;j<=m+1;j++)dp[i][j]=0;
    for(int i=1;i<=m;i++){
        for(int j=n;j>=1;j--){
            dp[j][i]=dp[j+1][i];
            if(a[j][i]=='I')dp[j][i]++;
        }
    }
    for(int i=1;i<=n;i++){
        for(int j=1;j<=m;j++){
            if(a[i][j]=='J'){
                int Z=dp[i+1][j];
                int R=suf[i][j+1];/*
                for(int k=i+1;k<=n;k++){
                    if(a[k][j]=='I')Z++;
                }*/
                /*
                for(int k=j+1;k<=m;k++){
                    if(a[i][k]=='O')R++;
                }*/
                ans+=Z*R;
            }
        }
    }
    cout<<ans;
}
// bitset fora?

• Subtask 1: 20 / 20
• Subtask 2: 30 / 30
• Subtask 3: 50 / 50