Leetcode 1323. 6 和 9 组成的最大数字 js&c&java

java 版

  public int maximum69Number (int num) {
    String str = String.valueOf(num);
    return Integer.valueOf(str.replaceFirst("6", "9"));
  }
  

js版

/**
 * @param {number} num
 * @return {number}
 */

  var maximum69Number  = function(num) {
    return +(num+'').replace("6", "9")
  };

c 版

int maximum69Number (int num){
    
    int a = 0;
    int index = -1;
    int num1 = num;
    while(num1 > 0){
        int left = num1 % 10;
        printf("\n %d left ", left);
        num1 = ( (num1 - left) / 10 );
        if(left == 6) index = a;
        a++;
    }
    // 数字中没有6 直接返回
    if(index < 0){
        return num;
    }
    
     printf("\n index = %d", index);
    
    int b = 0, res = 0;
    
    while(num > 0){
        int left = num % 10;
        if(b == index){
             res += pow(10, b) * 9;
        }else {
             res += pow(10, b) * left;
        }
        printf("\n b = %d", b);
        b++;
        num = ( (num - left) / 10 );
    }
    
    printf("\n res = %d", res);
    
    return res;
}


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