Dijkstra算法示例程序_1

好几天不写程序的结果就是以前的东西都忘得差不多了……o(╯□╰)o

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstdlib>
 4 #include <cstring>
 5 #include <cctype>
 6 #include <stack>
 7 #include <queue>
 8 #include <map>
 9 #include <set>
10 #include <vector>
11 #include <cmath>
12 #include <algorithm>
13 #define lson l, m, rt<<1
14 #define rson m+1, r, rt<<1|1
15 using namespace std;
16 typedef long long int LL;
17 const int MAXN =  0x7fffffff;
18 const int  MINN =  -0x7fffffff;
19 const double eps = 1e-9;
20 const int dir[8][2] = {{0,1},{1,0},{0,-1},{-1,0},{-1,1},
21   {1,1},{1,-1},{-1,-1}};
22 const int MAX = 20;
23 int S[MAX], dist[MAX], path[MAX], edge[MAX][MAX];
24 int n;
25 void Dijkstra(int v0) {
26   int i, j, k;
27   for (i = 0; i <n ; ++i) {
28     dist[i] = edge[v0][i]; S[i] = 0;
29     if (i != v0 && edge[v0][i] != MAXN) path[i] = v0;
30     else path[i] = -1;
31   }
32   S[v0] = 1; dist[v0] = 0;
33   for (i = 0; i < n - 1; ++i) {
34     int Min = MAXN, u = v0;
35     for (j = 0; j < n; ++j) {
36       if (dist[j] < Min && S[j] == 0) {
37         Min = dist[j]; u = j;
38       }
39     }
40     S[u] = 1;
41     for (j = 0; j < n; ++j) {
42       if (S[j] == 0 && edge[u][j] != MAXN) {
43         int tmp = edge[u][j] + dist[u];
44         if (tmp < dist[j]) {
45           dist[j] = tmp; path[j] = u;
46         }
47       }
48     }
49   }
50 }
51 int main(void){
52 #ifndef ONLINE_JUDGE
53   freopen("dijkstra.in", "r", stdin);
54 #endif
55   scanf("%d", &n);
56   int u, v, w, i, j, k;
57   memset(edge, 0, sizeof(edge));
58   while (1) {
59     scanf("%d%d%d", &u, &v, &w);
60     if (u == -1 && v == -1 && w == -1) break;
61     edge[u][v] = w;
62   }
63   for (i = 0; i < n; ++i) {
64     for (j = 0; j < n; ++j) {
65       if (i == j) edge[i][j] = 0;
66       else if (edge[i][j] == 0) edge[i][j] = MAXN;
67     }
68   }
69   Dijkstra(0);
70   for (i = 1; i < n; ++i) {
71     printf("%d\t", dist[i]);
72     int Shortest[MAX]; k = 0;
73     Shortest[k] = i; int po = path[i];
74     while (po != -1) {
75       Shortest[++k] = po; po = path[po];
76     }
77     for (j = k; j > 0; --j) {
78       printf("%d->", Shortest[j]);
79     }
80     printf("%d\n", Shortest[0]);
81   }
82 
83   return 0;
84 }

这次遇到的问题就是edge的初始化位置写错了,调好久。。

原文地址:https://www.cnblogs.com/liuxueyang/p/3072477.html