HDU 4284 Travel / 状态压缩DP

来源：互联网发布：互联网大数据济宁编辑：程序博客网时间：2024/05/22 11:33

最多15个必须经过的城市 2进制表示

dp[i][j] 表示i这个状态下现在位置是第j个城市剩下的最大钱数

我日啊 id有一个错了害我哇了12次一发现一改马上AC 伤不起

#include <cstdio>#include <cstring>#include <algorithm>using namespace std;const int maxn = 110;int INF = 999999999;struct Li{int u, c, d;}b[maxn];int dp[1<<16][16];int a[maxn][maxn];int id[maxn];int n, m, h, Money;void floyd(){for(int k = 1; k <= n; k++)for(int i = 1; i <= n; i++)for(int j = 1; j <= n; j++) if(a[i][k] + a[k][j] < a[i][j]) a[i][j] = a[i][k] + a[k][j];}int main(){int T;scanf("%d", &T);while(T--){scanf("%d %d %d", &n, &m, &Money);for(int i = 1; i <= n; i++){for(int j = 1; j <= n; j++){if(i == j)a[i][j] = 0;elsea[i][j] = INF;}}memset(id, 0, sizeof(id));while(m--){int u, v, w;scanf("%d %d %d", &u, &v, &w);if(a[u][v] > w){a[u][v] = w;a[v][u] = w;}}scanf("%d", &h);for(int i = 0; i < h; i++){scanf("%d %d %d", &b[i].u, &b[i].c, &b[i].d);id[i] = b[i].u;}memset(dp, -1, sizeof(dp));floyd();for(int i = 1; i < (1<<h); i++){for(int j = 0; j < h; j++){//dp[i][j] = INF;if(i&(1<<j)){if(i == (1<<j)){if(Money - a[1][id[j]] - b[j].d >= 0)dp[i][j] = Money - a[1][id[j]] - b[j].d + b[j].c;continue;}for(int k = 0; k < h; k++){if((i&(1<<k)) && (j != k)){if(dp[i^(1<<j)][k] == -1)continue;if(dp[i^(1<<j)][k] - a[id[k]][id[j]] - b[j].d >= 0){dp[i][j] = max(dp[i][j], dp[i^(1<<j)][k] - a[id[k]][id[j]] - b[j].d + b[j].c);//printf("%d %d %d\n", i, i^(1<<j), dp[i][j]);}}}}}}//for(int i = 0; i < h; i++)//printf("%d\n", dp[(1<<h)-1][i]);int ans = -1;for(int i = 0; i < h; i++)ans = max(ans, dp[(1<<h)-1][i] - a[id[i]][1]);if(ans >= 0)puts("YES");elseputs("NO");}return 0;}

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