L2-001. 紧急救援 多条最短路 spfa/dijkstra

#pragma comment(linker, "/STACK:1024000000,1024000000")
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll inf = 0x3f3f3f3f3f3f3f3f;
#define show(a) cout<<#a<<" = "<<a<<endl
#define show2(b,c) cout<<#b<<" = "<<b<<" "<<#c<<" = "<<c<<endl
#define show3(a,b,c) cout<<#a<<" = "<<a<<" "<<#b<<" = "<<b<<" "<<#c<<" = "<<c<<endl
#define show4(a,b,c,d) cout<<#a<<" = "<<a<<" "<<#b<<" = "<<b<<" "<<#c<<" = "<<c<<" "<<#d<<" = "<<d<<endl
const int maxn = 100005;
#define LOCAL

// 建议数组开大一些
int n, m, s, d;
int head[505*505], dis[505];
bool vis[505];// 点的总数

int nume = 0;
int ans = 0;

struct node {
int to, cost, next;
}e[505*505];// maxn的百倍以上 MAXM表示边的总数

void init() {
memset(vis, false, sizeof vis);
memset(dis, 0x3f, sizeof dis);
memset(head, -1, sizeof head);
memset(e, 0, sizeof e);
}

void add(int u, int v, int w) {
e[nume] = (node){v, w, head[u]};
head[u] = nume;
nume++;
}

int numq[505];

int num[505]; // 从出发点到i结点拥有的路的条数
int dui[505]; // 能找到的救援队的数目 边值的sum
int pre[505]; // 表示最短路径的前一个结点
int a[505]; // 每个结点的权值

bool spfa(int st, int ed) {
int to, cost, now;

/***/
queue<int> q;
q.push(st);
dis[st] = 0;
vis[st] = true;
/***/
num[st] = 1;
dui[st] = a[st];

while( !q.empty() ) {
/***/
now = q.front();
q.pop();
vis[now] = false;
/***/

for(int i = head[now]; ~i; i = e[i].next ) {
to = e[i].to;
cost = e[i].cost;

if( dis[to] > dis[now] + cost ) {
dis[to] = dis[now] + cost;

// num[to] = num[now]; // ==
dui[to] = dui[now] + a[to];
pre[to] = now;

if( !vis[to] ) {
numq[to]++;
if( numq[to] > n) return true;

vis[to] = true;
q.push(to);
}
}
else if( dis[to] == dis[now] + cost) {
// num[to] = num[to] + num[now]; // +=

if( dui[to] < dui[now] + a[to])
{
dui[to] = dui[now] + a[to];
pre[to] = now;

if( !vis[to] ) {
numq[to]++;
if( numq[to] > n) return true;

vis[to] = true;
q.push(to);
}
}

}
}
}
ans = dis[ed];
}

int numd = 0;
void dfs(int now) {// 计算最短路的条数
if( now == d )
{numd++; return;}
for(int i = head[now]; ~i; i = e[i].next ){
int to = e[i].to;
int cost = e[i].cost;

if( !vis[to] && dis[to] == dis[now] + cost)// 满足是最短路
{
vis[to] = 1;
dfs(to);
vis[to] = 0;
}
}
}

void print(int x) {
if( x == s )
{cout << x; return; }
print(pre[x]);
cout << ' ' << x;
}

int main() {
cin.tie(0);
ios::sync_with_stdio(false);
init();
cin >> n >> m >> s >> d;

for(int i = 0; i < n; i++)
cin >> a[i];

int u, v, w;
for(int i = 1; i <= m; i++) {
cin >> u >> v >> w;
add(u, v, w);
add(v, u, w);
}

spfa(s, d);
// cout << ans << endl;

memset(vis, 0, sizeof(vis)); dfs(s);
cout << numd << ' ' << dui[d] << endl;
// cout << num[d] << ' ' << dui[d] << endl;

print(d);
}

#include <cstdio>
#include <algorithm>
using namespace std;
int n, m, c1, c2;
int dis[510], weight[510], e[510][510], num[510], w[510], pre[510];
bool visit[510];
const int inf = 99999999;
void printPath(int v) {
if(v == c1) {
printf("%d", v);
return ;
}
printPath(pre[v]);
printf(" %d", v);
}
int main() {
scanf("%d%d%d%d", &n, &m, &c1, &c2);
for(int i = 0; i < n; i++)
scanf("%d", &weight[i]);
fill(e[0], e[0] + 510 * 510, inf);
fill(dis, dis + 510, inf);
int a, b, c;
for(int i = 0; i < m; i++) {
scanf("%d%d%d", &a, &b, &c);
e[a][b] = c;
e[b][a] = c;
}
dis[c1] = 0;
w[c1] = weight[c1];
num[c1] = 1;
for(int i = 0; i < n; i++) {
int u = -1, minn = inf;

for(int j = 0; j < n; j++) {
if(visit[j] == false && dis[j] < minn) {
u = j;
minn = dis[j];
}
}

if(u == -1) break;
visit[u] = true;

for(int v = 0; v < n; v++) {
if(visit[v] == false && e[u][v] != inf) {
if(dis[u] + e[u][v] < dis[v]) {
dis[v] = dis[u] + e[u][v];
num[v] = num[u];
w[v] = w[u] + weight[v];
pre[v] = u;
} else if(dis[u] + e[u][v] == dis[v]) {
num[v] = num[v] + num[u];
if(w[u] + weight[v] > w[v]) {
w[v] = w[u] + weight[v];
pre[v] = u;
}
}
}
}
}
printf("%d %d\n", num[c2], w[c2]);
printPath(c2);
return 0;
}