합승 택시 요금

https://programmers.co.kr/learn/courses/30/lessons/72413

코딩테스트 연습 - 합승 택시 요금

 

#include <string>
#include <vector>

using namespace std;

#define INF 987654321
const int MAX = 201;
int fare[MAX][MAX];
int N;

int Min(int a, int b) { if (a < b) return a; return b; }

void FindCheappest() {
	for (int i = 1; i <= N; i++) {
		for (int j = 1; j <= N; j++) {
			for (int k = 1; k <= N; k++) {
				if (i == j || i == k || j == k) continue;
				if(fare[j][i] != INF && fare[i][k] != INF)	fare[j][k] = Min(fare[j][k], fare[j][i] + fare[i][k]);
			}
		}
	}
}

int solution(int n, int s, int a, int b, vector<vector<int>> fares) {
	int answer = 0;

	N = n;

	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= n; j++) {
			fare[i][j] = 987654321;
		}
	}

	for (int i = 0; i < fares.size(); i++) {
		fare[fares[i][0]][fares[i][1]] = fares[i][2];
		fare[fares[i][1]][fares[i][0]] = fares[i][2];
	}
	for (int i = 1; i <= n; i++)	fare[i][i] = 0;

	FindCheappest();

	answer = fare[s][a] + fare[s][b];

	for (int i = 1; i <= n; i++) {
		if(fare[s][i] != INF && fare[i][a] != INF && fare[i][b] != INF)
			answer = Min(fare[s][i] + fare[i][a] + fare[i][b], answer);
	}
	return answer;
}