学步园

dfs求出 12345的所有全排列，然后模拟一下

写的比较搓。。。

#include <cstdio>
#include <iostream>
#include <cstring>
#include <algorithm>
#include <queue>
#include <stack>
#include <vector>
using namespace std;
typedef __int64 ll;
#define mod 1000000007
ll a[6][6];
int hash1[6],b[6];
ll m,cnt;
inline int Max(int a,int b){
    return a>b?a:b;
}
void Dfs(int x){
    if(x >= 5 ){
        int x1 = b[0];
        int x2 = b[1];
        int x3 = b[2];
        int x4 = b[3];
        int x5 = b[4];
        ll s =0;
        s += a[x1][x2] + a[x2][x1]+ a[x3][x4] + a[x4][x3];
        s += a[x2][x3] + a[x4][x5] + a[x3][x2] + a[x5][x4];
        s += a[x3][x4] + a[x4][x3];
        s += a[x4][x5] + a[x5][x4];
        m = Max(m,s);
        return ;
    }
    for(int i = 1;i <= 5;i++){
        if(hash1[i]) continue;
        hash1[i] = 1;
        b[x] = i;
        Dfs(x+1);
        hash1[i] = 0;
    }
}
int main(){
    for(int i = 1;i <= 5;i++){
        for(int j = 1;j <= 5;j++){
            scanf("%I64d",&a[i][j]);
        }
    }
    memset(hash1,0,sizeof(hash1));
    m = -1;
    Dfs(0);
    printf("%I64d\n",m);
    return 0;
}