def triangle ( A ):
    # write your code here
    A.sort()
    for i in range(len(A) - 2):
        if A[i] + A[i+1] > A[i+2]:
            return 1
    return 0

http://codility.com/contests/ep2010/results/appPZ2RXZ-B87

Task description:

Write a function
int triangle(int[] A);
which given a zero-indexed array A of n integers returns 1 if there exists triple i,j,k (, ) such that:

A[i] + A[j] > A[k] 

A[i] + A[k] > A[j] 

A[j] + A[k] > A[i] 
or returns 0 otherwise.
Examples: 
For:

A[0]=10, A[1]=2, A[2]=5, A[3]=1, A[4]=8, A[5]=20 
your function should return 1, since for i=0,j=2,k=4 all conditions are fullfiled (i.e. A[2]+A[4]>A[0]).
For:

A[0]=10, A[1]=50, A[2]=5, A[3]=1 
your function should return 0.

Determine whether a triangle can be built from a given set of edges

Python