#include <stdio.h>
#include <string.h>
 
int main() {
    const char *input_string = "12345abc";
    const char *compared_chars = "0123456789";
 
    size_t pos_first_diff = strspn(input_string, compared_chars);
    size_t pos_first_match = strcspn(input_string, compared_chars);
 
    printf("Input string: %s \tDigits: %s\n", input_string, compared_chars);
    printf("First digit different pos: %zu\n", pos_first_diff);
    printf("First digit matching pos: %zu\n", pos_first_match);
    return 0;
}

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

NDU=

45