Codeforces 1102F Elongated Matrix 状压dp

Elongated Matrix

预处理一下两两之间的最小值， 然后直接dp。

#include<bits/stdc++.h>
#define LL long long
#define fi first
#define se second
#define mk make_pair
#define PLL pair<LL, LL>
#define PLI pair<LL, int>
#define PII pair<int, int>
#define SZ(x) ((int)x.size())
#define ull unsigned long long

using namespace std;

const int N = 1e4 + 7;
const int inf = 0x3f3f3f3f;
const LL INF = 0x3f3f3f3f3f3f3f3f;
const int mod = 1e9 + 7;
const double eps = 1e-8;
const double PI = acos(-1);

int n, m;
int Mat[16][N];
int go[16][16];
int go2[16][16];
int dp[1 << 16][16];

int main() {
    scanf("%d%d", &n, &m);
    for(int i = 0; i < n; i++)
        for(int j = 0; j < m; j++)
            scanf("%d", &Mat[i][j]);
    int ans = 0;
    if(n == 1) {
        ans = inf;
        for(int i = 0; i < m - 1; i++) ans = min(ans, abs(Mat[0][i] - Mat[0][i + 1]));
        printf("%d
", ans);
        return 0;
    }
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < n; j++) {
            if(i == j) continue;
            go[i][j] = go2[i][j] = inf;
            for(int k = 0; k < m; k++)
                    go[i][j] = min(go[i][j], abs(Mat[i][k] - Mat[j][k]));
            for(int k = 0; k < m - 1; k++) {
                    go2[i][j] = min(go2[i][j], abs(Mat[i][k] - Mat[j][k + 1]));
            }
        }
    }
    for(int start = 0; start < n; start++) {
        memset(dp, -1, sizeof(dp));
        dp[1 << start][start] = inf;
        for(int S = 1; S < (1 << n); S++) {
            for(int i = 0; i < n; i++) {
                if(dp[S][i] < 0) continue;
                for(int j = 0; j < n; j++) {
                    if(S >> j & 1) continue;
                    dp[S|(1<<j)][j] = max(dp[S|(1<<j)][j], min(go[i][j], dp[S][i]));
                }
            }
        }
        for(int i = 0; i < n; i++)
                ans = max(ans, min(go2[i][start], dp[(1<<n)-1][i]));
    }
    printf("%d
", ans);
    return 0;
}

/*
*/