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#include <cstdio> #include <cstdlib> #include <cmath> #include <map> #include <set> #include <queue> #include <stack> #include <vector> #include <sstream> #include <string> #include <cstring> #include <algorithm> #include <iostream> #define maxn 100010 #define INF 0x7fffffff #define inf 100000000 #define MOD 1000000007 #define ULL unsigned long long #define LL long long using
namespace std; struct
edge { int
s, v, w; }p[6100]; int
n, m, w, d[510], num_p; void
addedge( int
a, int
b, int
c) { p[num_p].s = a; p[num_p].v = b; p[num_p].w = c; ++ num_p; } bool
bellom_form() { for ( int
i = 1; i <= n; ++ i) { d[i] = inf; } d[1] = 0; for ( int
i = 0; i < n-1; ++ i) { for ( int
j = 0; j < num_p; ++ j) { if (d[p[j].v] > d[p[j].s]+p[j].w) { d[p[j].v] = d[p[j].s]+p[j].w; } } } for ( int
i = 0; i < num_p; ++ i) { if (d[p[i].v] > d[p[i].s]+p[i].w) { return
true ; } } return
false ; } int
main() { int
t; scanf ( "%d" , &t); while (t --) { scanf ( "%d%d%d" , &n, &m, &w); num_p = 0; for ( int
i = 0; i < m; ++ i) { int
a, b, c; scanf ( "%d%d%d" , &a, &b, &c); addedge(a, b, c); addedge(b, a, c); } for ( int
i = 0; i < w; ++ i) { int
a, b, c; scanf ( "%d%d%d" , &a, &b, &c); addedge(a, b, -c); } if (bellom_form()) puts ( "YES" ); else
puts ( "NO" ); } return
0; } |
原文地址:http://www.cnblogs.com/avema/p/3774124.html