如题
1 #include<iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<queue> 5 #define rep(i,a,n) for(register int i = a;i <= n;++i) 6 using namespace std; 7 8 void read(int& a){ 9 a = 0;char c = getchar(); 10 while(c < '0'||c > '9')c = getchar(); 11 while('0' <= c&&c <= '9')a = a*10+c-'0',c = getchar(); 12 } 13 14 const int Maxn = 1e5+10,Maxm = 2e5+10; 15 16 template<typename T> 17 18 void iswap(T &a,T &b){ 19 T t = a; 20 a = b; 21 b = t; 22 } 23 24 template<typename T> 25 struct Heap{ 26 T a[1000010];int n; 27 Heap():n(0){} 28 int size(){return n;} 29 bool empty(){return !n;} 30 T top(){return a[1];} 31 void clear(){n = 0;} 32 33 void push(T x){ 34 a[++n] = x; 35 int cur = n; 36 while((cur>>1)&&a[cur>>1] < a[cur]) 37 iswap(a[cur>>1],a[cur]),cur >>= 1; 38 } 39 40 void pop(){ 41 iswap(a[1],a[n--]); 42 int cur = 1; 43 while((cur<<1|1) <= n) 44 if(a[cur<<1] < a[cur<<1|1]){ 45 if(a[cur] < a[cur<<1|1]){ 46 iswap(a[cur],a[cur<<1|1]); 47 cur = cur<<1|1; 48 } 49 else break; 50 } 51 else{ 52 if(a[cur] < a[cur<<1]){ 53 iswap(a[cur],a[cur<<1]); 54 cur <<= 1; 55 } 56 else break; 57 } 58 if((cur<<1) <= n&&a[cur] < a[cur<<1]) 59 iswap(a[cur],a[cur<<1]); 60 } 61 }; 62 63 struct Edge{ 64 int to,wi,ne; 65 }edges[Maxm]; 66 67 int first[Maxn],d[Maxn],vis[Maxn]; 68 int n,m,s,cnte,x,y,z; 69 70 inline void add_edge(int fr,int to,int wi){ 71 edges[++cnte] = (Edge){to,wi,first[fr]}; 72 first[fr] = cnte; 73 } 74 75 struct Node{ 76 int to,d; 77 bool operator <(const Node x)const{ 78 return d > x.d; 79 } 80 }; 81 82 Heap<Node> q; 83 84 inline void dijkstra(int s){ 85 memset(d,0x3f,sizeof(d)); 86 d[s] = 0; q.clear(); 87 q.push((Node){s,0}); 88 while(!q.empty()){ 89 int u = q.top().to; q.pop(); 90 if(vis[u])continue; vis[u] = 1; 91 for(register int i = first[u];i;i = edges[i].ne){ 92 if(d[edges[i].to] > d[u]+edges[i].wi){ 93 d[edges[i].to] = d[u]+edges[i].wi; 94 q.push((Node){edges[i].to,d[edges[i].to]}); 95 } 96 } 97 } 98 } 99 100 int main(){ 101 read(n),read(m),read(s); 102 rep(i,1,m){ 103 read(x),read(y),read(z); 104 add_edge(x,y,z); 105 } 106 dijkstra(s); 107 rep(i,1,n)printf("%d ",d[i]); 108 return 0; 109 }