백준 소스코드 [C++] 2325 개코전쟁

www.acmicpc.net/problem/2325

2325번: 개코전쟁

백준 소스코드 [C++] 2325 개코전쟁

#include <iostream>
#include <algorithm>
#include <queue>
#include <string.h>
#include <limits.h>
#include <vector>
#include <math.h>
#include <stack>
#include <bitset>
#include <string>
#include <set>
#include <map>
#include <unordered_map>
#include <sstream>
#include <cstdlib>
#define all(v) v.begin(), v.end()
#define pii pair<int, int>
#define pli pair<ll, int>
#define make_unique(v) sort(all(v)), v.erase(unique(all(v), v.end())
typedef long long ll;
using namespace std;

#define MAX 987654321
int V, E, v, e, weight;
vector <pii>adj[1001];
int result[1001], parent[1001];

void dijkstra(){
    
    for(int i=1;i<=1000;i++){
        result[i]=MAX;
        parent[i]=-1;
    }
    priority_queue<pii,vector<pii>, greater<pii>> pq;
    pq.push({0,1});
    result[1]=0;
    
    while(!pq.empty()){
        int here = pq.top().second;
        int cost = pq.top().first;
        pq.pop();
        
        if (result[here]<cost) continue;
        
        for(auto ith: adj[here]){
            int nextcost = cost + ith.second;
            int there = ith.first;
            
            if(result[there]>nextcost){
                result[there]=nextcost;
                parent[there]=here;
                pq.push({nextcost,there});
            }
        }
    }
}

int newDijkstra(int par, int child){
    
    for(int i=1;i<=1000;i++)result[i]=MAX;
    priority_queue<pii,vector<pii>, greater<pii>> pq;
    pq.push({0,1});
    result[1]=0;
    
    while(!pq.empty()){
        int here = pq.top().second;
        int cost = pq.top().first;
        pq.pop();
        
        if (result[here]<cost) continue;
        
        for(auto ith: adj[here]){
            int nextcost = cost + ith.second;
            int there = ith.first;
            if((there == par && here == child) || (here == par && there == child)) continue;
            if(result[there]>nextcost){
                result[there]=nextcost;
                pq.push({nextcost,there});
            }
        }
    }
    return result[V];
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    
    cin >> V >> E;
    
    for (int i = 0;i < E;i++) {
        cin >> v >> e >> weight;
        adj[v].push_back({ e,weight });
        adj[e].push_back({ v,weight });
    }
    
    dijkstra();
  
    int Mvalue = INT_MIN,here=V;
    while(parent[here]!=-1){
        Mvalue = max(Mvalue, newDijkstra(parent[here],here));
        here = parent[here];
    }
    cout<<Mvalue<<'\n';
    
    return 0;
}