poj 1860 Currency Exchange

dis数组写成int了 神他妈WA一下午…

bellman_ford求正环，人生第一条图论题…

#include <iostream>#define maxn 410#define inf 0x3f3f3f3fstruct edge{    int u, v;    double rate, com;}side[maxn];double dis[maxn];int edge_num, node_num, source;double value;void init() {    for(int i = 1; i <= edge_num; i++) {         dis[i] = 0;    }      dis[source] = value;}int bellman_ford() {    init();    for(int i = 0; i < edge_num; i++) {          for(int j = 1; j <= 2 * node_num; j++) {              if(dis[side[j].v] < (dis[side[j].u] - side[j].com) * side[j].rate){                  dis[side[j].v] = (dis[side[j].u] - side[j].com) * side[j].rate;              }          }      }      for(int j = 1; j <= 2 * node_num; j++) {          if(dis[side[j].v] < (dis[side[j].u] - side[j].com) * side[j].rate){              return 1;          }      }      return 0;  } int main(int argc, char *argv[]) {      //std::ios::sync_with_stdio(false);    std::cin >> edge_num >> node_num >> source >> value;    for(int i = 1; i <= 2 * node_num; i += 2) {        //std::cout << "BIU!\n";        std::cin >> side[i].u >> side[i].v >> side[i].rate >> side[i].com >> side[i+1].rate >> side[i+1].com;        side[i+1].u = side[i].v;        side[i+1].v = side[i].u;    }    if(bellman_ford()) {        std::cout << "YES\n";      } else {         std::cout << "NO\n";     }    return 0;}