Find a Fixed Point in a given array | GeeksforGeeks

This video is contributed by Harshit Jain.

[wecan]

class Solution{
public:

vector<int> valueEqualToIndex(int arr[], int n)
{
// int l=0;
// int r=n-1;
vector<int>v;
for(int i=0;i<n;i++)
{
if(arr[i]==i+1)
{
v.push_back(i+1);
}
}
return v;
}
};

[anshulsharma]

This solutio#2 doesn't work when there are more than 1 satisfying indexes e.g. [-5, -3, 2, 3, 7, 9, 10], as per the problem statement we need to return first index for which value matches the index.

[yogeshvaishnav]

2nd method doesn't hold good for all condition

[karanganwani]

what if an array contain multiple fixed point in it eg: arr = [0, 1, 2]

Then which method we should use ?

[narendrakanojia]

IN RUBY
arr.each_with_index do |a, i|
if arr[i] == i
res = i
break
else
res = -1
end
end

[goldbalaji]

lets assume mid =7 and a[mid] = 8 there is possibility for a[10] = 10 but you completely omitted that part of array ...

[zaffariqbal]

If there are duplicates values in the array then will this algorithm (binary search) work ?

[vishwaskumar]

If array integers are randomly arranged can we still able to get better solution than linear search???0(n)

[najisheqbal]

what if an array have two same value at same index than ???
{1, 1, 2, 5, 8}
now does it work ??? reply please

[saikiranreddymekala]

if array is of {0, 1, 2} then method 2 doesn't work....