CF938D Buy a Ticket

Posted 2023-01-01 lyt020321

4 2
1 2 4
2 3 7
6 20 1 25

6 14 1 25 

3 3
1 2 1
2 3 1
1 3 1
30 10 20

12 10 12 

思路:

建立虚点把点券转化成边权

#include <iostream>
#include <stdio.h>
#include <string.h>
#include <algorithm>
#include <queue>
#define int long long
#define maxn 850500
using namespace  std ;
int read() 
    int x = 0 , f = 1 ; char s = getchar() ;
    while(s > '9' || s < '0') if(s == '-') f = -1 ; s = getchar() ;
    while(s <='9' && s >='0') x = x * 10 + (s-'0'); s = getchar() ;
    return x*f ;    

int n , m ;
struct dy 
    int x , y ,z  ,next ;
a[maxn] ;
int head[maxn] , vis[maxn] , dis[maxn] , t ;
void add(int x ,int y ,int z) 
    a[++t].x = x ;
    a[t].y = y ;
    a[t].z = z ;
    a[t].next = head[x] ;
    head[x] = t ;

typedef pair<int,int>pa ;
priority_queue<pa,vector<pa>,greater<pa> >q ;
void dij(int s) 
    memset(dis,0x3f,sizeof(dis)) ;
    memset(vis,0,sizeof(vis)) ;
    dis[s] = 0 , vis[s] = 0 ;
    q.push(make_pair(dis[s],s)) ;
    while(!q.empty()) 
        int u = q.top().second ;
        q.pop() ;
        if(vis[u]) continue ;
        vis[u] = 1 ;
        for(int i = head[u] ; i ; i = a[i].next ) 
            int v = a[i].y ;
            if(dis[v] > dis[u] + a[i].z ) 
                dis[v] = dis[u] + a[i].z ;
                q.push(make_pair(dis[v],v)) ;
            
        
    

signed main () 
    n = read() , m = read() ;
    while(m --) 
        int x = read() , y = read() , z = read() ;
        add(x,y,z*2) ;
        add(y,x,z*2) ;
    
    for(int i = 1 ; i <= n ; i ++) 
        int x = read() ;
        add(0,i,x) ;
        add(i,0,x) ;
    dij(0) ;
    for(int i = 1 ; i <= n ; i ++) 
        printf("%I64d ",dis[i]) ;
    
    return 0 ;