hdu 1690最短路
就是建图,把题目描述的东东转换成一张图求最短路就行了,因为是随机询问,所以用floyd比较方便。不过打完之后一直WA,百思不得其解的情况下看了一下discuss,有人说得用long long,于是我马上改了交,果然过了……唉,以后看题还是得细心……
/* * hdu1690/win.cpp * Created on: 2012-10-27 * Author : ben */ #include <cstdio> #include <cstdlib> #include <cstring> #include <cmath> #include <ctime> #include <iostream> #include <algorithm> #include <queue> #include <set> #include <map> #include <stack> #include <string> #include <vector> #include <deque> #include <list> #include <functional> #include <numeric> #include <cctype> using namespace std; typedef long long LL; const int MAXN = 105; const LL INF = 0x7fffffffffffffffLL; LL graph[MAXN][MAXN]; int N; void Floyd() { int i, j, k; for (k = 0; k < N; k++) { for (i = 0; i < N; i++) { for (j = 0; j < N; j++) { if(graph[i][k] < graph[i][j] - graph[k][j]) { graph[i][j] = graph[i][k] + graph[k][j]; } } } } } void buildgraph(int &M) { fill_n((LL *)graph, MAXN * MAXN, INF); int L[4], C[4], pos[MAXN]; for(int i = 0; i < 4; i++) { scanf("%d", &L[i]); } for(int i = 0; i < 4; i++) { scanf("%d", &C[i]); } scanf("%d%d", &N, &M); for(int i = 0; i < N; i++) { scanf("%d", &pos[i]); } for(int i = 0; i < N; i++) { graph[i][i] = 0; for(int j = i + 1; j < N; j++) { int t = abs(pos[i] - pos[j]); for(int k = 0; k < 4; k++) { if(t <= L[k]) { int p = C[k]; graph[i][j] = graph[j][i] = p; break; } } } } } int main() { #ifndef ONLINE_JUDGE freopen("data.in", "r", stdin); #endif int T, M, a, b; scanf("%d", &T); for(int t = 1; t <= T; t++) { printf("Case %d:\n", t); buildgraph(M); Floyd(); for(int i = 0; i < M; i++) { scanf("%d%d", &a, &b); if(graph[a - 1][b - 1] == INF) { printf("Station %d and station %d are not attainable.\n", a, b); }else { printf("The minimum cost between station %d and station %d is %I64d.\n", a, b, graph[a - 1][b - 1]); } } } return 0; }