palindromeIndex

#include <assert.h>
#include <limits.h>
#include <math.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

char* readline();

// Complete the palindromeIndex function below.
int palindromeIndex(char* s) {
    int l=strlen(s), Eliminated=0, DelIdx=0, Found=0;

    for(int p=0; p<2 && Found==0; p++){
        Eliminated = 0;
        for(int i=0, j=l-1;i<l/2 && Eliminated < 2; i++, j--){
            // confronto l'i-esimo con l'omologo carattere j-esimo
            if (s[i] != s[j]){
                // sono diversi, quindi devo decidere quale eliminare
                if(p==0){
                    if(s[i]==s[j-1]){
                        // va eliminato j (prima passata)
                        DelIdx = j;
                        // ... ma i non deve cambiare al prossimo giro
                        i--;
                    } else {
                        // va eliminato i (prima passata)
                        DelIdx = i;
                        // ma j non deve cambiare al prossimo giro
                        j++;
                    }
                } else {
                    if(s[j]==s[i+1]){
                        // va eliminato i (seconda passata)
                        DelIdx = i;
                        // ma j non deve cambiare al prossimo giro
                        j++;
                    } else {
                        // va eliminato j (seconda passata)
                        DelIdx = j;
                        // ... ma i non deve cambiare al prossimo giro
                        i--;
                    }
                }
                Eliminated++;
            }
        }
        Found = (Eliminated == 1? 1: 0);
    }

    return (Eliminated != 1? -1: DelIdx);
}



int main()
{
    FILE* fptr = fopen(getenv("OUTPUT_PATH"), "w");

    char* q_endptr;
    char* q_str = readline();
    int q = strtol(q_str, &q_endptr, 10);

    if (q_endptr == q_str || *q_endptr != '\0') { exit(EXIT_FAILURE); }

    for (int q_itr = 0; q_itr < q; q_itr++) {
        char* s = readline();

        int result = palindromeIndex(s);

        fprintf(fptr, "%d\n", result);
    }

    fclose(fptr);

    return 0;
}

char* readline() {
    size_t alloc_length = 1024;
    size_t data_length = 0;
    char* data = malloc(alloc_length);

    while (true) {
        char* cursor = data + data_length;
        char* line = fgets(cursor, alloc_length - data_length, stdin);

        if (!line) { break; }

        data_length += strlen(cursor);

        if (data_length < alloc_length - 1 || data[data_length - 1] == '\n') { break; }

        size_t new_length = alloc_length << 1;
        data = realloc(data, new_length);

        if (!data) { break; }

        alloc_length = new_length;
    }

    if (data[data_length - 1] == '\n') {
        data[data_length - 1] = '\0';
    }

    data = realloc(data, data_length);

    return data;
}