UVA 11691 - Allergy Test(状压dp+贪心)

#include <stdio.h>
#include <string.h>
#include <map>
#include <algorithm>
using namespace std;
#define INF 0x3f3f3f3f
#define min(a,b) ((a)<(b)?(a):(b))
#define max(a,b) ((a)>(b)?(a):(b))
const int N = 25;
const int M = (1<<20) + 5;
int t, n, num[N], dp[M][8];

int dfs(int s, int k) {
    if (dp[s][k] != -1) return dp[s][k];
    dp[s][k] = INF;
    if (s == (1<<n) - 1) return dp[s][k] = 0;
	int vis[8];
	memset(vis, 0, sizeof(vis));
    for (int i = 0; i < n; i++) {
		if (vis[num[i]]) continue;
        if (s&(1<<i)) continue;
		vis[num[i]] = 1;
        int t = dfs(s^(1<<i), max(0, num[i] - k - 1)) + max(1, num[i] - k);
        dp[s][k] = min(dp[s][k], t);
    }
    return dp[s][k];
}

int main() {
    scanf("%d", &t);
    while (t--) {
        scanf("%d", &n);
		memset(dp, -1, sizeof(dp));
        for (int i = 0; i < n; i++)
            scanf("%d", &num[i]);
        printf("%d\n", dfs(0, 0));
    }
    return 0;
}