解题思路

题目要求用 switch 语句。输入 1~7，用 switch 匹配，输出对应的星期英文名称。

参考代码

#include <iostream>
using namespace std;

int main() {
    int n;
    cin >> n;
    switch (n) {
        case 1: cout << "Monday" << endl; break;
        case 2: cout << "Tuesday" << endl; break;
        case 3: cout << "Wednesday" << endl; break;
        case 4: cout << "Thursday" << endl; break;
        case 5: cout << "Friday" << endl; break;
        case 6: cout << "Saturday" << endl; break;
        case 7: cout << "Sunday" << endl; break;
    }
    return 0;
}

复杂度分析

switch 只匹配一次，时间复杂度 O(1)，额外空间复杂度 O(1)。