// 1844. Replace All Digits with Characters #include "leetcode.h" /* * given a 0-indexed string 's' that has lowercase english letters in its even * indices and digits in its odd indices. there is a function 'shift(x, c)' * where 'x' is a character and 'c' is an integer that returns the c'th * character after 'x'. for every odd index 'i', you want to replace the digit * 's[i]' with shift(s[i - 1], s[i]). return 's' after replacing all digits. */ char *replaceDigits(char *s) { int n = strlen(s); for (int i = 1; i < n; i++) s[i] += s[i - 1] - '0'; return s; } int main() { char *s1 = "a1c1e1", *s2 = "a1b2c3d4e"; printf("%s\n", replaceDigits(s1)); // expect: abcdef printf("%s\n", replaceDigits(s2)); // expect: abbdcfdhe }