100131. 使三个字符串相等

⭐ AC code

class Solution {
    public int findMinimumOperations(String s1, String s2, String s3) {
        int len1 = s1.length();
        int len2 = s2.length();
        int len3 = s3.length();
        int n = Math.min(len1,len2);
        n = Math.min(n,len3);
        int i = 0;
        while(i < n)
        {
            if(s1.charAt(i) != s2.charAt(i) || s2.charAt(i) != s3.charAt(i))
                break;
            i++;
        }
    if(i == 0)
        return -1;
    return len1 + len2 + len3 - i * 3;
    }
}

100122. 区分黑球与白球

⭐ AC code

class Solution {
    public long minimumSteps(String s) {
        long ans = 0;
        long cnt = 0;
        for(int i = 0; i < s.length(); i++)
        {
            char c = s.charAt(i);
            if(c == '0')
                ans += cnt;
            else
                cnt++;
        }
        return ans;
    }
}

100119. 最大异或乘积

⭐ AC code

import java.math.BigDecimal;
class Solution {
    public int maximumXorProduct(long a, long b, int n) {

        int mod = (int) (1e9 + 7);

        BigDecimal pre = BigDecimal.valueOf(a).multiply(BigDecimal.valueOf(b));
        for (int i = n - 1; i >= 0; i--) {

            long a1 = a ^ (1L << i);
            long b1 = b ^ (1L << i);
            BigDecimal cur = BigDecimal.valueOf(a1).multiply(BigDecimal.valueOf(b1));
            if (cur.subtract(pre).doubleValue() > 0) {
                a = a1;
                b = b1;
                pre = cur;
            }
        }

        long a1 = (a) % mod;
        long b1 = (b) % mod;

        return (int) (a1 * b1 % mod);

    }
}

👨‍🏫 大佬题解