poj 1511

模拟链表，稀疏图的dij

#include <iostream>
#include <cstdio>
#include <iomanip>
#include <string>
#include <cstdlib>
#include <cstring>
#include <queue>
#include <set>
#include <vector>
#include <map>
#include <algorithm>
#include <cmath>
#include <stack>

#define INF 0x3f3f3f3f
#define LINF 0x3f3f3f3f3f3f3f3f
#define ll long long
#define ull unsigned long long
#define uint unsigned int
#define l(x) ((x)<<1)
#define r(x) ((x)<<1|1)
#define lowbit(x) ((x)&(-(x)))
#define abs(x) ((x)>=0?(x):(-(x)))
#define ms(a,b) memset(a,b,sizeof(a))
#define NSYNC std::ios::sync_with_stdio(false);std::cin.tie(0);std::cout.tie(0);

using namespace std;

const int maxn = 1000010;

struct edges {
	int end, val,next;
} e[maxn],re[maxn];

struct node {
	int my, val;
	node(int vv,int dd):my(vv),val(dd){}
	bool operator<(const node &m) const {
		return val > m.val;
	}
};

ll n,m,len,rlen,head[maxn],rhead[maxn],d[maxn];
int uesd[maxn];
ll ans;
int a, b, c,t;

void add(int start, int end, int val) {
	e[len].end = end;
	e[len].next = head[start];
	e[len].val = val;
	head[start] = len++;
}

void radd(int start, int end, int val) {
	re[rlen].end = end;
	re[rlen].next = rhead[start];
	re[rlen].val = val;
	rhead[start] = rlen++;
}

void dij(int s) {
	ms(d, INF);
	ms(uesd, 0);
	d[s] = 0;
	priority_queue<node> q;
	q.push(node(s, 0));
	while (!q.empty()) {
		s = q.top().my;
		q.pop();
		if (uesd[s])continue;
		uesd[s] = 1;
		for (int j = head[s]; j; j = e[j].next) {
			int end = e[j].end;
			int val = e[j].val;
			if (!uesd[end] && d[end] > d[s] + val) {
				d[end] = d[s] + val;
				q.push(node(end, d[end]));
			}
		}
	}
}

int main(){
	scanf("%d", &t);
	while (t--) {
		len = rlen = 1;
		ms(head, 0);
		ms(rhead, 0);
		scanf("%d%d", &n, &m);
		for (int i = 0; i < m; i++) {
			scanf("%d%d%d", &a, &b, &c);
			add(a, b, c);
			radd(b, a, c);
		}

		ans = 0;
		dij(1);
		for (int i = 1; i <= n; i++) ans += d[i];
		memcpy(head, rhead, sizeof(rhead));
		memcpy(e, re, sizeof(re));
		dij(1);
		for (int i = 1; i <= n; i++)ans += d[i];

		printf("%lld\n", ans);
	}

	return 0;
}