CodinGame_2023_08_22__15_17_00__n_chars.c

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#include <ctype.h>

/**
    Line 1: A sequence of two alphabetic characters. sep
    Line 2: A sequence of alpha-numeric characters. serie

    Example:

    >>> md
    >>> md5fg27dm5p

    Between the first letter m and the last letter d, we have the values 5 and 27.
    Thus, we obtain: 5 + 27 = 32

    Examples :
    sm
    k36sD4fs65Nd46mKv56v465dmW46d

    636

 **/

int main()
{
    char sep[3];
    scanf("%[^\n]", sep); fgetc(stdin);
    char serie[256];
    scanf("%[^\n]", serie);
    int idxFirst = 0;
    int idxLast = 0;
    for (int i = 0; i < strlen(serie); i++) {
        if (serie[i] == sep[0]) {
            idxFirst = i;
            break;
        }
    }
    for (int i = strlen(serie)-1; i > 0; i--) {
        if (serie[i] == sep[1]) {
            idxLast = i;
            break;
        }
    }
    int sum = 0;
    for (int i = idxFirst; i < idxLast; i++) {
        if (isdigit(serie[i])) {
            sum += serie[i] - '0';
        }
    }
    printf("%d\n", sum);
    return 0;
}