place plus/minus signs between the digits (on C)

signs_digits .c

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int current_sum = 0;

/* return pointer on vector with random numbers*/
int* get_rnd1d_vector(const int *count_num, const int *max_num){/*{{{*/
    int* vector = malloc((*count_num) * sizeof(int));
    for (int i = 0; i < (*count_num); ++i)
    {
        vector[i] = rand() % (*max_num);
        /*global variable the current_summ for a test*/
        current_sum = current_sum + vector[i]*((rand() % 2)? 1 : -1);
    };
    printf("current sum: %d \n", current_sum);
    return vector;
}/*}}}*/

/* return sum a vector*/
int get_full_sum(const int * this_vector, const int *count_num){/*{{{*/
    int this_sum = 0;
    for(int i = 0; i < (*count_num); i++){
        this_sum = this_sum + this_vector[i];
    };
    return this_sum;
} /*}}}*/

int get_sign(int * this_vector, int i, int this_sum){/*{{{*/
    if (i){
        if(get_sign(this_vector, i - 1, this_sum + this_vector[i - 1])){
            printf("+%d",this_vector[i - 1]);
            return 1;
        }
        else if(get_sign(this_vector, i - 1, this_sum - this_vector[i - 1])){
            this_vector[i - 1] = -this_vector[i - 1];
            printf("%d",this_vector[i - 1]);
            return 1;
        };
        return 0;
    };
    return current_sum == this_sum;
}/*}}}*/

int main(){
    const int count_num = 24;
    const int max_num = 50000000;
    
    /* 24*5*10^7 = 1.2*10^9 and 1*10^9 */
    const int max_sum = 1000000000; 

    int * this_vector = get_rnd1d_vector(&count_num, &max_num);

    if(abs(current_sum) > max_sum){
        printf("\noverflow sum\n");
        free(this_vector);
        return 0;
    };

    if(get_sign(this_vector, count_num, 0)){
        printf("\ntest current sum: %d \n", get_full_sum(this_vector, &count_num));
    } else {
        printf("\nNo solution");
    };
    printf("\nand here\n");
    free(this_vector);
    return 0;
}