题解 | #最大数字交换#

直接对着题目翻译

public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param num string字符串 
     * @return string字符串
     */
    static bool cmp(const int &a, const int &b) {
        return a > b;
    }
    string maximumSwap(string num) {
        // write code here
        string str1;
        int a[1000500];
        int len = num.size();
        for (int i = 0; i < len; i++) {
            a[i] = num[i] - '0';
        }
        sort(a, a + len, cmp);
        for (int i = 0; i < len; i++) {
            str1 += a[i] + '0';
        }
        int mark = 0;
        for (int i = 0; i < len; i++) {
            if (num[i] != str1[i]) {
                mark = i;
                break;
            }
        }
        int mark1 = 0;
        for (int i = 0; i < len; i++) {
            if (str1[mark] == num[i]) {
                mark1 = i;
            }
        }
        char temp = num[mark];
        num[mark] = num[mark1];
        num[mark1] = temp;
        return num;
    }
};