How does it prints the value 3?

#1

3 is not present inside the array and it’s and according to the code it helps to find the first occurrence of 3 but 3 is not present so according to me it should print 0, but it is printing 3.Can’t understand the logic please help.

#2

Hey due some technical issue, question is not visible to me, if you could provide me the question It would help me in solving your doubt.

#3

int main() { int arr[5] = { 4, 5, 1, 0, 1 }; sort( arr, arr+5 ); cout<< lower_bound( arr, arr+5, 3 ) - arr <<endl; return 0; }

#4

Lower_bound functions returns the iterator/pointer to the first element that is equal or greater than the given element. In your code array after sorting is: 0 1 1 4 5
Now we 4 is the first element that is bigger than 3, so lower_bound will return iterator to that position. You are subtracting the return value with arr, so your final output will become index of 4 which is 3.