SMMR-170: Salesman

#include <bits/stdc++.h>
using namespace std;
const int INF = 1e9;
int n, Bit;
int x[28],y[28];
vector <vector<int>> dp(262153, vector<int>(28,INF));
int distance(int i, int j){
    return (x[i] - x[j])*(x[i] - x[j]) + (y[i] - y[j])*(y[i] - y[j]);
}
int salesman(int bit, int i){
    if(bit == Bit) return distance(i,1);
    if(dp[bit][i] != INF) return dp[bit][i];

    for(int j=1; j<=n; j++){
        if(bit & (1<<(j-1)) ) continue;
        dp[bit][i] = min(dp[bit][i], distance(i,j) + salesman(bit | (1<<(j-1)), j));
    }
    return dp[bit][i];
}
int main(){

    scanf("%d",&n);
    for(int i=1; i<=n; i++){
        scanf("%d%d",&x[i],&y[i]);
    }
    Bit = (1<<n) - 1;
    printf("%d",salesman(1,1));

    return 0;
}