50236. String Merge

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "mergeString.h"

void mergeString(char** p, char l[26], char* a){
    int rank[26];
    for(int i = 0; i < 26; i++) rank[l[i] - 'a'] = i;

    int n = 0;
    while(p[n] != NULL) n++;

    int a_ptr = 0;
    while(1){
        int max_idx = -1, max_pri = 50;
        for(int i = 0; i < n; i++){
            char ch = *(p[i]);
            if(ch == '\0') continue;
            if(rank[ch - 'a'] < max_pri){
                max_idx = i, max_pri = rank[ch - 'a'];
            }
        }
        if(max_idx == -1) break;
        else{
            a[a_ptr++] = *(p[max_idx]);
            p[max_idx]++;
        }
    }
}