[DP(Top-Down)] 백준 2098 외판원 순회(TSP) C++

 

https://www.acmicpc.net/problem/2098

2098번: 외판원 순회

재귀 DP

#include <iostream>
#include <vector>
#include <cstring>
#define MAXN 100000
#define INF 1000000000

using namespace std;

int n, s, w[16][16], dp[16][MAXN];

int tsp(int u, int v) {
	if (v == (1 << n) - 1) {
		if (w[u][s] == 0) w[u][s] = INF;
		return w[u][s];
	}

	int& ret = dp[u][v];
	if (ret != -1) return ret;

	ret = INF;
	for (int i = 0; i < n; i++) {
		if (v & (1 << i)) continue;
		if (w[u][i] == 0) continue;
		ret = min(ret, tsp(i, v | (1 << i)) + w[u][i]);
	}
	return ret;
}

int main() {
	ios_base::sync_with_stdio(0); 
	cin.tie(NULL); cout.tie(NULL);

	memset(dp, -1, sizeof(dp));

	cin >> n;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			cin >> w[i][j];
		}
	}

	cout << tsp(0, 1);
}