#include <stdio.h>
#include <string.h>
#include <stdlib.h>
void capitalize_first_last(char *arr, int len) {
int *idx = (int *)malloc(len * sizeof(int));
idx[0] = 1;
idx[len - 1] = 1;
for (int i = 1; i < len; i++){
if (arr[i] == ' ') {
idx[i - 1] = 1;
idx[i + 1] = 1;
}
}
for (int i = 0; i < len; i++) {
if (idx[i] == 1)
arr[i] -= 32;
}
free(idx);
}
int main() {
char arr[] = "abcd efgh ijkl";
capitalize_first_last(arr, strlen(arr));
printf("%s\n", arr);
return 0;
}
/*
run:
AbcD EfgH IjkL
*/