【基础练习⊇字符串】C001_字串对比（枚举|库函数）



二、题解

方法一&＃xff1a;

import java.util.*;
public class Main{ public static void main(String[] args) { Scanner sc &＃61; new Scanner(System.in);String s1 &＃61; sc.next();String s2 &＃61; sc.next();if (s1.length() !&＃61; s2.length()) {System.out.println(1);return;}if (s1.equals(s2)) {System.out.println(2);return;}char[] S1 &＃61; s1.toCharArray();char[] S2 &＃61; s2.toCharArray();int cnt &＃61; 0;for (int i &＃61; 0; i < s1.length(); i&＃43;&＃43;) {if (S1[i] &＃61;&＃61; S2[i] || S1[i] &＃43; 32 &＃61;&＃61; S2[i] || S1[i] - 32 &＃61;&＃61; S2[i]) {cnt&＃43;&＃43;;}}if (cnt &＃61;&＃61; S1.length) {System.out.println(3); return; }else System.out.println(4);}
}

复杂度分析

• 时间复杂度&＃xff1a;$O(n)$&＃xff0c;
• 空间复杂度&＃xff1a;$O(1)$&＃xff0c;

方法二&＃xff1a;库函数

• 在验证提条件3时&＃xff0c;直接使用以下语句简化代码&＃xff1a;

s1.toLowerCase().equals(s2.toLowerCase()) && !s1.equals(s2)