Find a range that covers all the elements of given N ranges in C++

Suppose we have a n ranges containing L and R. We have to check or find the index of 0 – based of the range which covers all the other given n – 1 ranges. If there is no such range, display -1. For example, if L = [2, 4, 3, 1], and R = [4, 6, 7, 9], then the output is 3. So it means the range at 3rd index (1 to 9) covers all the elements of other n – 1 ranges.

Since all L and R points are distinct, find the range of smallest L and largest R point, if both are the same range, then it indicates all other ranges lie within it. Otherwise it is not possible.

Example

 Live Demo

#include<iostream> using namespace std; int fact (int n) {    if (n == 0)       return 1;    return n * fact(n-1); } void showRange(int n) {    int a = fact(n + 2) + 2;    int b = a + n - 1;    cout << "[" << a << ", " << b << "]"; } int main() {    int n = 3 ;    showRange(n); }

Output

[122, 124]