// 1903. Largest Odd Number in String #include "leetcode.h" /* * given a string 'num' representing a large integer. return the largest-valued * odd integer as a string is a non-empty substring of 'num', or an empty string * "" if no odd integer exists. a substring is a contiguous sequence of * characters within a string */ char *largestOddNumber(char *num) { int n = strlen(num); for (int i = n - 1; i >= 0; i--) if ((num[i] - '0') % 2 == 1) { num[i + 1] = '\0'; return num; } return ""; } int main() { char *n1 = "52", *n2 = "4206", *n3 = "35427"; printf("%s\n", largestOddNumber(n1)); // expect: 5 printf("%s\n", largestOddNumber(n2)); // expect: NULL printf("%s\n", largestOddNumber(n3)); // expect: 35427 }