Submission #776212

#	Time	Username	Problem	Language	Result	Execution time	Memory
776212		DobromirAngelov	Bitaro the Brave (JOI19_ho_t1)	C++14	100 / 100	245 ms	89488 KiB

joi2019_ho_t1

#include<bits/stdc++.h>
#define endl '\n'

using namespace std;

const int MAXN=3005;

int n,m;
string s[MAXN];
int pref[2][MAXN][MAXN];

int main()
{
ios::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);

cin>>n>>m;
for(int i=0;i<n;i++)
{
    cin>>s[i];
}

for(int i=0;i<n;i++)
{
    for(int j=0;j<m;j++)
    {
        if(j>0) pref[0][i][j]=pref[0][i][j-1];
        if(s[i][j]=='O') pref[0][i][j]++;
    }
}

for(int j=0;j<m;j++)
{
    for(int i=0;i<n;i++)
    {
        if(i>0) pref[1][i][j]=pref[1][i-1][j];
        if(s[i][j]=='I') pref[1][i][j]++;
    }
}

long long ans=0;
for(int i=0;i<n;i++)
{
    for(int j=0;j<m;j++)
    {
        if(s[i][j]=='J') ans+=(pref[0][i][m-1]-(j>0 ? pref[0][i][j-1] : 0)) * (pref[1][n-1][j]-(i>0 ? pref[1][i-1][j] : 0));
    }
}

cout<<ans<<endl;

return 0;
}

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