LQDRECT - Đếm hình chữ nhật
Tác giả: flashmt
Ngôn ngữ: C++
#include<iostream>
int main()
{
int m,n,i,j,k,f[310][310],a[310],x,num;
long long re;
re=0;
scanf("%d%d",&m,&n);
for (j=1;j<n;j++)
for (k=j+1;k<=n;k++)
f[j][k]=0;
for (i=1;i<=m;i++)
{
num=0;
for (j=1;j<=n;j++)
{
scanf("%d",&x);
if (x)
{
for (k=1;k<=num;k++)
{
re+=f[a[k]][j];
f[a[k]][j]++;
}
num++;
a[num]=j;
}
}
}
printf("%lld\n",re);
// system("pause");
return 0;
}