1534. Count the triples (C++)
1 topic description
Give you an integer array arr, and three integers a, b, and c. Please count the number of good triples.
If the triple (arr[i], arr[j], arr[k]) satisfies all the following conditions, it is considered a good triple.
0 <= i <j <k <arr.length
|arr[i] -arr [j]| <= a
|arr[j]-arr[k]| <= b
|arr[i]-arr[k] | <= c
where |x| represents the absolute value of x.
Returns the number of good triples.
2 Example description
2.1 Example 1
Input: arr = [3,0,1,1,9,7], a = 7, b = 2, c = 3
Output: 4
Explanation: There are 4 good triples: [(3,0,1 ), (3,0,1), (3,1,1), (0,1,1)].
2.2 Example 2
Input: arr = [1,1,2,2,3], a = 0, b = 0, c = 1
Output: 0
Explanation: There is no triple that meets all conditions.
3 Problem solving tips
3 <= arr.length <= 100
0 <= arr[i] <= 1000
0 <= a, b, c <= 1000
4 Detailed source code (C++)
class Solution {
public:
int countGoodTriplets(vector<int>& arr, int a, int b, int c) {
int count = 0 ;
for (int i = 0 ; i < arr.size() - 2 ; i ++ )
{
for (int j = i + 1 ; j < arr.size() - 1 ; j ++ )
{
if ( abs( arr[i] - arr[j] ) <= a )
{
for (int k = j + 1 ; k < arr.size() ; k ++ )
{
if ( abs( arr[j] - arr[k] ) <= b && abs( arr[i] - arr[k] ) <= c )
{
count++;
}
}
}
}
}
return count ;
}
};