HDU-4522 湫湫系列故事——过年回家 最短路
题意:很乱
分析:把数据处理下,dijkstra下就行了,floyd超时了,我还想着优化一下输入,因为使用了vector和string等等,但是计算数据规模后,处理输入的时间复杂度比floyd要低一个数量级,看来还是要换成dijkstra了。
#include <cstdlib> #include <cstdio> #include <cstring> #include <algorithm> #include <vector> #include <string> using namespace std; const int N = 205; const int inf = 0x3f3f3f3f; int n, m, D1, D2, A, B; vector<string>vs[2]; int mp1[N][N]; int mp2[N][N]; void conn(int mp[][N], const string & s, int val) { int t = 0; vector<int>vt; for (int i = 0; i < s.length(); ++i) { if (s[i] != '+') t = t * 10 + s[i] - '0'; else { vt.push_back(t); t = 0; } } vt.push_back(t); for (int i = 0; i < (int)vt.size(); ++i) { for (int j = i+1; j < (int)vt.size(); ++j) { mp[vt[i]][vt[j]] = min(mp[vt[i]][vt[j]], val*(j-i)); } } } int dis[N]; char vis[N]; int dijkstra(int mp[][N]) { memset(dis, 0x3f, sizeof (dis)); memset(vis, 0, sizeof (vis)); dis[A] = 0; for (int i = 0; i < n; ++i) { int Min = inf, p; for (int j = 1; j <= n; ++j) { if (!vis[j] && Min > dis[j]) { Min = dis[j]; p = j; } } if (p == B) break; vis[p] = 1; for (int j = 1; j <= n; ++j) { if (!vis[j] && dis[p]+mp[p][j] < dis[j]) { dis[j] = dis[p] + mp[p][j]; } } } return dis[B]; } void solve() { memset(mp1, 0x3f, sizeof (mp1)); memset(mp2, 0x3f, sizeof (mp2)); for (int i = 0; i < (int)vs[0].size(); ++i) { conn(mp1, vs[0][i], D1); } for (int i = 0; i < (int)vs[1].size(); ++i) { conn(mp1, vs[1][i], D1); conn(mp2, vs[1][i], D2); } int ans = min(dijkstra(mp1), dijkstra(mp2)); printf(ans == inf ? "-1\n" : "%d\n", ans); } int main() { int T, k; char str[10005]; scanf("%d", &T); while (T--) { vs[0].clear(); vs[1].clear(); scanf("%d %d", &n, &m); for (int i = 0; i < m; ++i) { scanf("%s %d", str, &k); if (k == 0) vs[0].push_back(str); else vs[1].push_back(str); } scanf("%d %d %d %d", &D1, &D2, &A, &B); solve(); } return 0; }