TechoSagar: Count possible triangles

Search

Google Alert - jobs

Count possible triangles

Given an unsorted array of positive integers. Find the number of triangles that can be formed with three different array elements as lengths of three sides of triangles. 
Input: 
The first line of the input contains T denoting the number of testcases. First line of test case is the length of array N and second line of test case are its elements.

Output:
Number of possible triangles are displayed to the user.

Constraints:
1 <=T<= 100
3 <=N<= 100
1 <=arr[i]<= 1000

Example:
Input:
2
3
3 5 4
5
6 4 9 7 8
Output:
1
10
Your Code
#include<iostream>

using namespace std;

int main()
{
int t;
cin>>t;
while(t--)
{
int i;
int a[1000];
int n;
cin>>n;
for(i=0; i<n; i++)
{
cin>>a[i];
}
int num=0;
int j, k;
for(i=0; i<n-2; i++)
{
for(j=i+1; j<n-1; j++)
{
for(k=j+1; k<n; k++)
{
if((a[i]+a[j])>a[k] && (a[k]+a[j])>a[i] && (a[i]+a[k])>a[j])
num++;
}
}
}
cout<<num<<endl;
}
}

Follow us

Follow Bijendra Kumar on Facebook