#include <stdio.h> int main() { char str[200]; int freq[256] = {0}; // histogram array int i; printf("Enter a string: "); fgets(str, sizeof(str), stdin); // Count frequency of each character for (i = 0; str[i] != ''; i++) { unsigned char ch = str[i]; freq[ch]++; } // Print non-zero frequencies printf("nCharacter frequencies:n"); for (i = 0; i < 256; i++) { if (freq[i] > 0) { if (i == 'n') printf("\n : %dn", freq[i]); else if (i == ' ') printf("space : %dn", freq[i]); else printf("%c : %dn", i, freq[i]); } } return 0; }