蓝桥 审美课

#include<bits/stdc++.h>
using namespace std;

map<int,int> ans;

int main()
{
    ios::sync_with_stdio(false);
    int n,m;
    cin>>n>>m;
    for(int i=0;i<n;i++)
    {
        int a=0;
        for(int j=0;j<m;j++)
        {
            int x;
            cin>>x;
            a=a<<1;
            a+=x;
        }
        ans[a]++;
    }
    int sum =0;
    int maxn = (1<<m)-1;
    for(map<int,int>::iterator it=ans.begin(); it!=ans.end();it++)
    {
        int x = it->first;
        int num = x^maxn;
        sum += ans[num]*it->second;
    }
    cout<<sum/2;
    return 0;
}

标签：false,cout,int,审美,蓝桥,num,ans
来源： https://www.cnblogs.com/magicalzh/p/10485511.html