// 1323. Maximum 69 Number #include "leetcode.h" /* * you are given a positive integer 'num' consisting only of digit 6 and 9. * return the maximum number you can get by changing at most one digit. (6 * becomes 9, and 9 becomes 6). */ int maximum69Number(int num) { int right = -1, cnt = 0, tmp = num; while (tmp > 0) { int digits = tmp % 10; if (digits == 6) right = cnt; cnt++; tmp /= 10; } if (right == -1) return num; int ans = num + (3 * pow(10, right)); return ans; } int main() { printf("%d\n", maximum69Number(9669)); // expect: 9969 printf("%d\n", maximum69Number(9996)); // expect: 9999 printf("%d\n", maximum69Number(9999)); // expect: 9999 }