Give array A with sorted data. A value of each index of A is unique.
Find which A index is equal to A value.
EX
Array index : 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12
Array value : -3, -2, -1, 0, 4, 6, 8, 10, 12, 14, 16, 18, 20
Answer A[4] = 4
Hint Binary search