I having problem with my searching function C++ - c++

Question

i'am begginner in C++, i want to ask question about what's wrong about my coding, when i doing my work then found out problem i can't solve in searching function, there's no error notice or anything from visual studio but my function still didn't work,
sorry for my bad english.
here is my full code
#include <iostream>
#include <cstdlib>
#define MAX 5
using namespace std;
struct College {
int nim;
string name;
}mahasiswa;
struct queue {
College college[MAX];
int start,end = - 1;
}antrean;
void init() {
antrean.start= -1;
antrean.end = -1;
}
bool full() {
if (antrean.end== MAX - 1) {
return true;
}
else {
return false;
}
}
bool empty() {
if (antrean.end== -1) {
return true;
}
else {
return false;
}
}
void tampilData() {
int i;
if (!empty()) {
for (i = antrean.start; i < antrean.end; i++)
{
cout<<antrean.college[i].nim<<" | ";
cout << antrean.college[i].name << " | ";
cout << "\n";
}
}
cout<<"\n";
}
void inQueue() {
tampilData();
int elemennim;
string elemenname;
if (!full()) {
cout << "Input your NIM : ";
cin >> elemennim;
cout << "\n";
cout << "Input your name: ";
cin >> elemenname;
cout << "\n";
cout << "Succefully\n";
antrean.college[antrean.end].nim = elemennim;
antrean.college[antrean.end].name = elemenname;
antrean.end++;
}
else
{
cout << "Queue Penuh\n";
}
}
and this the error function i cant solve,
void searching(int key) {
for (int i = 0; i <= antrean.start; i++)
{
if (key == antrean.college[i].nim) {
cout << "Element found in index " << i;
}
else
{
cout << "Element not found\n";
}
cout << antrean.college[i].nim;
}
}
int main() {
int choice, elemen;
init();
cout << "Demo Queue dengan Linear Array" << endl;
do {
tampilData();
cout << "\nMenu Utama\n";
cout << "==============\n";
cout << "[1] Init \n[2] InQueue \n[3] Searching \n[4] out \n";
cout << "==============\n";
cout << "\nMasukkan pilihan: "; cin >> choice;
cout << "==============\n";
switch (choice) {
case 1: init(); break;
case 2: inQueue(); break;
case 3: cout << "masukkan NIM yang ingin dicari \n";
cin >> choice;
searching(choice); break;
} while (choice != 0);
return 0;
}
please help me, thank you very much