提供两种spfa算法模板
1.链表储存：
1 /*--------------------------spfa链表储存*/ 2 const int N = 10100 ; 3 4 struct Edge{ 5 int to,w,nxt; 6 }e[100010]; 7 int head[N],p; 8 int dis[N]; 9 bool vis[N]; 10 queue <int> q; 11 12 void spfa(int a) //a点到其他点的最短距离 13 { 14 memset(dis,0x3f,sizeof(dis)); 15 vis[a] = true; 16 q.push(a); 17 dis[a] = 0; 18 while(!q.empty()) 19 { 20 int d = q.front(); 21 for(int i = head[d]; i ;i = e[i].nxt) 22 { 23 int w = e[i].w ,v = e[i].to; 24 if(dis[d] + w < dis[v]) 25 { 26 dis[v] = dis[d] + w; 27 if(!vis[v]) 28 { 29 q.push(v); 30 vis[v] = true ; 31 } 32 } 33 } 34 q.pop(); 35 vis[d] = false ; 36 } 37 }
2.数组储存
1 /*----------------------------------spfa数组储存*/ 2 const int N = 1010 ; 3 int map[N][N]; 4 int dis[N]; 5 bool vis[N]; 6 int n; 7 queue <int> q; 8 9 void spfa(int a) 10 { 11 memset(dis,0x3f,sizeof(dis)); 12 q.push(a); 13 vis[a] = true; 14 dis[a] = 0; 15 while(!q.empty()) 16 { 17 int d = q.front(); 18 for(int i=1;i<=n;++i) 19 { 20 if(map[d][i]!=0 && map[d][i]+dis[d] < dis[i]) 21 { 22 dis[i] = dis[d] + map[d][i]; 23 if(!vis[i]) 24 { 25 q.push(i); 26 vis[i] = true; 27 } 28 } 29 } 30 q.pop(); 31 vis[d] = false ; 32 } 33 }