### LeetCode Challenge #287. Find the Duplicate Number

Given an array of integers `nums` containing `n + 1` integers where each integer is in the range `[1, n]` inclusive.

There is only one repeated number in `nums`, return this repeated number.

You must solve the problem without modifying the array `nums` and uses only constant extra space.

Example 1:

```Input: nums = [1,3,4,2,2]
Output: 2
```

Example 2:

```Input: nums = [3,1,3,4,2]
Output: 3
```

Constraints:

• `1 <= n <= 105`
• `nums.length == n + 1`
• `1 <= nums[i] <= n`
• All the integers in `nums` appear only once except for precisely one integer which appears two or more times.
##### Video Solution
###### Java Solution
```				```
class Solution {
public int findDuplicate(int[] nums) {

int ans = 0 ;

for(int i=0;i<nums.length;i++){
int ele = nums[i];
ele = Math.abs(ele);

if(nums[ele]>0){
nums[ele]=-nums[ele];
}else{
ans =  ele ;
break;
}
}

for(int i=0;i<nums.length;i++){
nums[i]=Math.abs(nums[i]);
}

return ans ;
}
}
```
```