【最短路】 HDOJ 1535 Invitation Cards

#include <iostream>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <bitset>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <climits>
#include <cstdlib>
#include <cmath>
#include <time.h>
#define maxn 1000005
#define maxm 1000005
#define eps 1e-10
#define mod 998244353
#define INF 1e17
#define lowbit(x) (x&(-x))
#define mp mark_pair
#define ls o<<1
#define rs o<<1 | 1
#define lson o<<1, L, mid
#define rson o<<1 | 1, mid+1, R
typedef long long LL;
//typedef int LL;
using namespace std;
LL powmod(LL a, LL b){LL res=1,base=a;while(b){if(b%2)res=res*base%mod;base=base*base%mod;b/=2;}return res;}
void scanf(int &__x){__x=0;char __ch=getchar();while(__ch==' '||__ch=='\n')__ch=getchar();while(__ch>='0'&&__ch<='9')__x=__x*10+__ch-'0',__ch = getchar();}
// head

struct Edge
{
int u, v, c;
}edges[maxm];
struct node
{
int x;
LL d;
bool operator < (const node &a) const {
return a.d < d;
}
}now, tmp;
priority_queue<node> q;
int h[maxn], next[maxm], v[maxm], cost[maxm];
int vis[maxn];
int n, m, cnt;
LL dis[maxn];

void read(void)
{
scanf(n), scanf(m);
//scanf("%d%d", &n, &m);
for(int i = 0; i < m; i++) scanf(edges[i].u), scanf(edges[i].v), scanf(edges[i].c);
//scanf("%d%d%d", &edges[i].u, &edges[i].v, &edges[i].c);
}
void init(void)
{
cnt = 0;
memset(h, -1, sizeof h);
memset(vis, 0, sizeof vis);
for(int i = 0; i <= n; i++) dis[i] = INF;
}
void addedges(int u, int vv, int c)
{
next[cnt] = h[u], h[u] = cnt, v[cnt] = vv, cost[cnt] = c, cnt++;
}
void dijstra(int s)
{
dis[s] = 0, tmp.x = s, tmp.d = 0, q.push(tmp);
while(!q.empty()) {
now = q.top(); q.pop();
if(vis[now.x]) continue;
vis[now.x] = 1;
for(int e = h[now.x]; ~e; e = next[e])
if(dis[v[e]] > dis[now.x] + cost[e]) {
dis[v[e]] = dis[now.x] + cost[e];
tmp.x = v[e], tmp.d = dis[v[e]];
q.push(tmp);
}
}
}
void work(void)
{
LL ans = 0;
init();
for(int i = 0; i < m; i++)
addedges(edges[i].u, edges[i].v, edges[i].c);
dijstra(1);
for(int i = 1; i <= n; i++) ans += dis[i];
init();
for(int i = 0; i < m; i++)
addedges(edges[i].v, edges[i].u, edges[i].c);
dijstra(1);
for(int i = 1; i <= n; i++) ans += dis[i];
printf("%I64d\n", ans);
}
int main(void)
{
int _;
while(scanf("%d", &_)!=EOF) {
while(_--) {
read();
work();
}
}
return 0;
}