Array of structs: dinamic allocation (.cpp)

#include <iostream>
#include <string.h>
#include "dinalloc.h"

using namespace std;

// returns -1 if the element 'str' doesn't exist in the array
// otherwise it returns the position of the element
int exist(hi *v, int n, str s) {
    int i = 0;
    while ((strcmp(v[i].name, s) != 0) && (i < n))
        i++;

    if (i == n)
        return -1;
    else
        return i;
}

void loadHistogram(hi *v, int &n) {
    int newcap = 0; // number of the item without duplicates
    for (int i = 0; i < n; i++) {
        str s;
        cout << "Enter a name: ";
        cin >> s;

        if (exist(v, n, s) == -1) { // if not exist it is a new item
            strcpy(v[newcap].name, s);
            v[newcap].cnt = 1;
            newcap++;
        } else // otherwise it exists, so increase the counter
            v[exist(v, n, s)].cnt++;
    }

    n = newcap; // set the array cap with the real number of items (without duplicates)
}

void printHistogram(hi *v, int n) {
    for (int i = 0; i < n; i++) {
        cout << v[i].name << "\t\t" << v[i].cnt << " ";

        for (int j = 0; j < v[i].cnt; j++)
            cout << "o";
        cout << endl;
    }
}