(入门组)寒假每日一题 Week2

AcWing 756. 蛇形矩阵 (星期一)

分析

定义方向上右下左, 然后res里放元素即可

联动leetcode54

code

#include <iostream>
#include <vector>
using namespace std;
const int N = 110;
int n, m;

int main(){
    scanf("%d%d", &n, &m);
    int d = 1;
    int dx[] = {-1, 0, 1, 0}, dy[] = {0, 1, 0, -1};
    int x = 0, y = 0;
    vector<vector<int>> res(n, vector<int>(m));
    for (int i = 1; i <= n * m; i ++ ){
        res[x][y] = i;
        int a = x + dx[d], b = y + dy[d];
        if (a < 0 || a >= n || b < 0 || b >= m || res[a][b]){
            d = (d + 1) % 4;
            a = x + dx[d], b = y + dy[d];
        }
        x = a, y = b;
    }
    for (int i = 0; i < n; i ++ ){
        for (int j = 0; j < m; j ++ )
            cout << res[i][j] << ' ';
        cout << endl;
    }
    return 0;   
}