// 2109. Adding Spaces to a String #include "leetcode.h" /* * given a 0-indexed string 's' and a 0-indexed integer array 'spaces' that * describes the indices in the original string where spaces will be added. each * space should be inserted before the character at the given index. return the * modified string after the spaces have been added */ char *addSpaces(char *s, int *spaces, int spacesSize) { int n = strlen(s), m = n + spacesSize + 1; char *ans = (char *)malloc(m * sizeof(char)); ans[m - 1] = '\0'; int aidx = 0, bidx = 0; int *num = (int *)malloc(spacesSize * sizeof(int)); num[0] = spaces[0]; for (int i = 1; i < spacesSize; i++) num[i] = spaces[i] - spaces[i - 1]; for (int i = 0; i < spacesSize; i++) { strncpy(&ans[aidx], &s[bidx], num[i]); aidx += num[i]; bidx += num[i]; ans[aidx] = ' '; aidx++; } strncpy(&ans[aidx], &s[bidx], m - aidx); free(num); return ans; } int main() { char *s1 = "LeetcodeHelpsMeLearn", *s2 = "icodeinpython", *s3 = "spaceing"; int n1[] = {8, 13, 15}, n2[] = {1, 5, 7, 9}, n3[] = {0, 1, 2, 3, 4, 5, 6}; printf("%s\n", addSpaces(s1, n1, ARRAY_SIZE(n1))); // expect: Leetcode Helps Me Learn printf("%s\n", addSpaces(s2, n2, ARRAY_SIZE(n2))); // expect: i code in py thon printf("%s\n", addSpaces(s3, n3, ARRAY_SIZE(n3))); // s p a c i n g }