hdu_2544

最短路裸题，dijkstra+邻接表水过#include <cstdio>#include <cstring>#include <algorithm>using namespace std;#define MAXN102#define MAXM10001#define INF 0x3f3f3f3fstruct Edge {int v, w, next;}edge[MAXM];int e_cnt, head[MAXN], dis[MAXN], used[MAXN];void insert_arc(int u, int v, int w){edge[e_cnt].w = w;edge[e_cnt].v = v;edge[e_cnt].next = head[u];head[u] = e_cnt ++;swap(u, v);edge[e_cnt].w = w;edge[e_cnt].v = v;edge[e_cnt].next = head[u];head[u] = e_cnt ++;}int dijkstra(int src, int des, int vertex){int u, v, min_val;fill(dis, dis+vertex+1, INF);memset(used, 0, sizeof(used));for(int i = head[src]; -1 != i; i = edge[i].next) {v = edge[i].v;dis[v] = min(dis[v], edge[i].w);}used[src] = 1;dis[src] = 0;for(int i = 1; i < vertex; i ++) {min_val = INF;for(int j = 1; j <= vertex; j ++) {if( !used[j] && min_val > dis[j] ) {min_val = dis[j];u = j;}}used[u] = 1;for(int j = head[u]; -1 != j; j = edge[j].next) {v = edge[j].v;if( !used[v] && dis[v] > dis[u]+edge[j].w ) {dis[v] = dis[u]+edge[j].w;}}}return dis[des];}int main(int argc, char const *argv[]){#ifndef ONLINE_JUDGEfreopen("test.in", "r", stdin);#endifint vertex, arc, u, v, w;while( scanf("%d %d", &vertex, &arc) && vertex && arc ) {e_cnt = 0; memset(head, -1, sizeof(head));for(int i = 0; i < arc; i ++) {scanf("%d %d %d", &u, &v, &w);insert_arc(u, v, w);}printf("%d\n", dijkstra(1, vertex, vertex));}return 0;}