15684 사다리 조작

문제 링크

#include <bits/stdc++.h>

using namespace std;

int n, m, h;
vector<vector<int>> ladder;

void print_ladder() {
    cout << "print_ladder\n";
    for (int r = 1; r <= h; r++) {
        for (int c = 1; c <= n; c++) {
            if (ladder[r][c] == 1)
                cout << "├";
            else if (ladder[r][c] == -1)
                cout << "┤";
            else
                cout << "│";
        }
        cout << "\n";
    }
    cout << "\n";
}

int run_simul() {
    print_ladder();
    for (int c = 1; c <= n; c++) {
        int tC = c;
        for (int r = 1; r <= h; r++)
            tC += ladder[r][tC];
        if (tC != c)
            return false;
    }
    cout << "SUCCESS\n";
    return true;
}

int dfs(int cnt, int row, int col) {
    if (!cnt) {
        return run_simul();
    }
    int ret = 0;
    for (int r = row; r <= h; r++) {
        for (int c = col; c < n; c++) {
            if (!(ladder[r][c] || ladder[r][c + 1])) {
                ladder[r][c] = 1;
                ladder[r][c + 1] = -1;
                ret = dfs(cnt - 1, r, c);
                if (ret)
                    return ret;
                ladder[r][c] = 0;
                ladder[r][c + 1] = 0;
            }    
        }
    }
    return ret;
}

int solve() {
    for (int cnt = 0; cnt <= m; cnt++) {
        cout << "cnt : " << cnt << "\n";
        if (dfs(cnt, 1, 1))
            return cnt;
    }
    return -1;
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    int a, b;
    cin >> n >> m >> h;
    ladder.resize(h + 1, vector<int>(n + 1, 0));
    for (int i = 0; i < m; i++) {
        cin >> a >> b;
        ladder[a][b] = 1;
        ladder[a][b + 1] = -1;
    }
    cout << solve() << "\n";
}

dfs 시작점을 어떻게 해야 중복된 순회를 하지 않을까

3항 연산자!

문제 잘 읽자 3개…………