Hackerrank - Minimum Distances

Consider an array of  integers, . The distance between two indices,  and , is denoted by .

Given , find the minimum  such that  and . In other words, find the minimum distance between any pair of equal elements in the array. If no such value exists, print .

Note:  denotes the absolute value of .

Input Format

The first line contains an integer, , denoting the size of array . 
The second line contains  space-separated integers describing the respective elements in array .

Constraints

Output Format

Print a single integer denoting the minimum  in ; if no such value exists, print .

Sample Input

6
7 1 3 4 1 7

Sample Output

3

Explanation 
Here, we have two options:

•  and  are both , so .
•  and  are both , so .

The answer is .

Solution:

1. #include <bits/stdc++.h>
2. using namespace std;
3.  
4. int last_index[100001];
5.  
6. int main(){
7.     int n, x;
8.     scanf("%d", &n);
9.     int distance = INT_MAX;
10.     for(int i = 1; i <= n; i++){
11.         scanf("%d", &x);
12.         if(last_index[x])distance = min(distance, i-last_index[x]);
13.         last_index[x] = i;
14.     }
15.     if(distance == INT_MAX)distance = -1;
16.     printf("%d\n", distance);
17.     return 0;
18. }