Question

How to count the unique characters in a string with C

Answer 1

#include <stdio.h>
#include <string.h>

int count_unique_char(char* p) {
	int ascii[256] = { 0 };
	int size = strlen(p);

	for (int i = 0; i < size; i++) {
		ascii[p[i]] = 1;
	}

    int count = 0;
	for (int i = 0; i < 256; i++) {
		count += ascii[i];
	}

	return count;

}

int main() {
	char str[64] = "javascript typescript node.js c c++";

	printf("%d", count_unique_char(str));
	
	return 0;
}





/*
run:

17

*/

 

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