PAT-A 1003. Emergency (25)

来源：互联网发布：python安装后怎么用编辑：程序博客网时间：2024/06/04 00:32

注意点：
一个单源最短路算法，需要考虑两个条件，最短路和最多队伍，有优先级。用spfa。

代码：

#include <iostream>#define max_Int 1<<30using namespace std;struct Road{  int d;   int l; };struct Line{  int p;   int l;  int t; };int main(){  int n, m, c1, c2;  int team[500];  struct Road road[501][501];  struct Line line[100000];  int con[500];  int left, right;  int i, j, i1, i2, i3, i4;  int num, ans, minl;  cin >> n >> m >> c1 >> c2;  for (i = 0; i < n; i++)  {    cin >> team[i];    road[i][0].d = 0;    con[i] = max_Int;  }  for (i = 0; i < m; i++)  {    cin >> i1 >> i2 >> i3;    road[i1][0].d++;    i4 = road[i1][0].d;    road[i1][i4].d = i2;    road[i1][i4].l = i3;    road[i2][0].d++;    i4 = road[i2][0].d;    road[i2][i4].d = i1;    road[i2][i4].l = i3;  }  left = 0; right = 0;  con[c1] = 0;  line[0].p = c1;  line[0].l = 0;  line[0].t = team[c1];  while (left <= right)  {    if (line[left].l > con[line[left].p])    {      left++;      continue;    }    for (i = 1; i <= road[line[left].p][0].d; i++)    {      if (line[left].l + road[line[left].p][i].l > con[road[line[left].p][i].d])      {        continue;      }      else      {        con[road[line[left].p][i].d] = line[left].l + road[line[left].p][i].l;        right++;        line[right].p = road[line[left].p][i].d;        line[right].l = con[road[line[left].p][i].d];        line[right].t = line[left].t + team[road[line[left].p][i].d];      }    }    left++;  }  minl = con[c2];  ans = 0;  num = 0;  for (i = 0; i <= right; i++)  {    if (line[i].p == c2 && line[i].l == minl)    {      num++;      if (line[i].t > ans)        ans = line[i].t;    }  }  cout << num << " " << ans << endl;  return 0;}

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