ticket office problem

Question

MY CODE IS NOT WORKING FOR TEST CASE 4 ONLY
You are working on a ticketing system. A ticket costs $10.
The office is running a discount campaign: each group of 5 people is getting a discount, which is determined by the age of the youngest person in the group.
You need to create a program that takes the ages of all 5 people as input and outputs the total price of the tickets.

Sample Input:
55
28
15
38
63

Sample Output:
42.5

The youngest age is 15, so the group gets a 15% discount from the total price, which is $50 - 15% = $42.5
The given code is declaring an array of 5 elements and taking them from input using a loop.

#include <iostream>
using namespace std;

int main() {
int ages[5];
for (int i = 0; i < 5; ++i) {
cin >> ages[i];
}
int e =0;
double total=50.0;
int u=0;
for (int y =0; y < 5; y++){
if (ages[0] < ages[u] && ages[0] <= ages[0]){
e =ages[0];
}
else if (ages[1] < ages[u] && ages[1] <= ages[0]){
e =ages[1];
}
else if (ages[2] < ages[u] && ages[2] <= ages[0]){
e =ages[2];
}
else if (ages[3] < ages[u] && ages[3] <= ages[0]){
e =ages[3];
}
else if (ages[4] < ages[u] && ages[4] <= ages[0]){
e =ages[4];
}
else{
e=ages[y];
}
u++;
}
double t= e*total/100;
double r = 50 - t;
cout<<r;
return 0;
}

Answer 1

the cause of error is finding wrong lowest age.
why are you doing roughly about 50 comparisons to find the minimum? let's assume e = ages[0] then go from ages[1] to ages[4] to see if any of them is smaller than e.

test cases that pass are due to their arrangement, but suppose you get:
ages = {5,3,9,7,8}
your loop gives 5 as minimum because
ages[0] < ages[u] when u = 0 is false therefore e = 0
ages[1] < ages [u] is false
this goes until e = ages[y] that is e = 5
now u is 1
ages[0] < ages[u] is false (5 < 3)
ages[1] < ages[u] is false (3 < 3)
...
when u is 0 first if is always false
when u is 1 second if is always false
etc.
hope this helps.