【DP】 HDOJ 4284 Travel

来源：互联网发布：mac下载汉仪颜体编辑：程序博客网时间：2024/05/17 17:14
先用floyd预处理出全源最短路，然后状压DP就可以了。。。
#include <iostream>#include <queue> #include <stack> #include <map> #include <set> #include <bitset> #include <cstdio> #include <algorithm> #include <cstring> #include <climits>#include <cstdlib>#include <cmath>#include <time.h>#define maxn 105#define maxm 10005#define eps 1e-7#define mod 1000000007#define INF 0x3f3f3f3f#define PI (acos(-1.0))#define lowbit(x) (x&(-x))#define mp make_pair#define ls o<<1#define rs o<<1 | 1#define lson o<<1, L, mid #define rson o<<1 | 1, mid+1, R#define pii pair<int, int>#pragma comment(linker, "/STACK:16777216")typedef long long LL;typedef unsigned long long ULL;//typedef int LL;using namespace std;LL qpow(LL a, LL b){LL res=1,base=a;while(b){if(b%2)res=res*base;base=base*base;b/=2;}return res;}LL powmod(LL a, LL b){LL res=1,base=a;while(b){if(b%2)res=res*base%mod;base=base*base%mod;b/=2;}return res;}// headint dp[16][1 << 16];int g[maxn][maxn];int a[maxn];int c[maxn];int p[maxn];int d[maxn];int n, m, o, money;void init(){memset(g, INF, sizeof g);}void read(){int u, v, cc;scanf("%d%d%d", &n, &m, &money);while(m--) {scanf("%d%d%d", &u, &v, &cc);g[u][v] = min(g[u][v], cc);g[v][u] = min(g[v][u], cc);}for(int i = 0; i <= n; i++) g[i][i] = 0;scanf("%d", &m);for(int i = 0; i < m; i++) {scanf("%d%d%d", &a[i], &c[i], &d[i]);p[i] = 1 << i;}o = 1 << m;}void work(){for(int k = 1; k <= n; k++)for(int i = 1; i <= n; i++)for(int j = 1; j <= n; j++)g[i][j] = min(g[i][j], g[i][k] + g[k][j]);for(int i = 0; i < m; i++)for(int j = 0; j < o; j++)dp[i][j] = -INF;for(int i = 0; i < m; i++)if(money - g[1][a[i]] - d[i] >= 0)dp[i][p[i]] = max(dp[i][p[i]], money - g[1][a[i]] - d[i] + c[i]);for(int i = 0; i < o; i++)for(int j = 0; j < m; j++)if(dp[j][i] >= 0)for(int k = 0; k < m; k++) {if(i & p[k]) continue;if(dp[j][i] - d[k] - g[a[j]][a[k]] >= 0)dp[k][i | p[k]] = max(dp[k][i | p[k]], dp[j][i] - d[k] - g[a[j]][a[k]] + c[k]);}int ans = -INF;for(int i = 0; i < m; i++) ans = max(ans, dp[i][o - 1] - g[a[i]][1]);if(ans >= 0) printf("YES\n");else printf("NO\n");}int main(){int _;scanf("%d", &_);while(_--) {init();read();work();}return 0;}
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