1018 Public Bike Management 30

#include <cstdio>
#include <vector>
#include <algorithm>
#include <cstring>
using namespace std;
const int maxn = 510;
const int INF = 1000000000;
int c, tgt, n, m, G[maxn][maxn], bikeNum[maxn];
int dis[maxn],vis[maxn]={0},minNeed = INF, minRemain = INF;
vector<int> path,tempPath;
vector<int> pre[maxn];

int findNotFoundMin(){
    int minIdx=-1,minDis=INF;
    for(int i = 0; i <= n; i++){
        if(vis[i] == 0 && dis[i] < minDis){
            minDis = dis[i];
            minIdx = i;
        }
    }
    return minIdx;
}

void Dijkstra(){
    
    fill(dis, dis+maxn, INF);
    dis[0] = 0;
    for(int i = 0; i <= n; i++){
        int min = findNotFoundMin();
        if(min == -1) break;
        vis[min] = 1;
        for(int j = 0; j <= n; j++){
            if(vis[j] == 0 && G[min][j] != INF){
                if(G[min][j]+dis[min] < dis[j]){
                    dis[j] = G[min][j]+dis[min];
                    pre[j].clear();
                    pre[j].push_back(min);
                }else if(G[min][j]+dis[min] == dis[j]){
                    pre[j].push_back(min);
                }
            }
        }
    }
}
void DFS(int v){
    if(v == 0){
        tempPath.push_back(v);
        int need=0,remain=0;
        for(int i = tempPath.size()-1; i >= 0; i--){
            int idx = tempPath[i];
            if(bikeNum[idx] > 0){
                remain += bikeNum[idx];
            }else{
                if(remain > abs(bikeNum[idx])){
                    remain -= abs(bikeNum[idx]);
                }else{
                    need += abs(bikeNum[idx]) - remain;
                    remain = 0;
                }
            }
        }
        if(need < minNeed){
            minNeed = need;
            minRemain = remain;
            path = tempPath;
        }else if(need == minNeed && remain < minRemain){
            minRemain = remain;
            path = tempPath;
        }
        tempPath.pop_back();
        return;
    }
    tempPath.push_back(v);
    for(int i = 0; i < pre[v].size(); i++){
        DFS(pre[v][i]);
    }
    tempPath.pop_back();
}
int main() {
    scanf("%d%d%d%d", &c, &n, &tgt, &m);
    int si,sj,t;
    int tmp;
    for(int i = 1; i <= n; i++){
        scanf("%d", &tmp);
        bikeNum[i] = tmp - c / 2;
    }
    fill(G[0], G[0]+maxn*maxn, INF);
    for(int i = 0; i < m; i++){
        scanf("%d%d%d", &si, &sj, &t);
        G[si][sj] = t;
        G[sj][si] = t;
    }
    Dijkstra();
    DFS(tgt);
    printf("%d ", minNeed);
    for(int i = path.size()-1; i >= 0; i--){
        printf("%d", path[i]);
        if(i > 0){
            printf("->");
        }
    }
    printf(" %d\n", minRemain);
    return 0;
}