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### by Sumit Chourasia | Sep 26, 2020 | Category :coding | Tags : algorithmarrayडेटा-संरचनाआसानleetcode

#### Fibonacci Number - Array - Easy - LeetCode - मिनी टीवी

The Fibonacci numbers, commonly denoted F(n) form a sequence, called the Fibonacci sequence, such that each number is the sum of the two preceding ones, starting from 0 and 1. That is,

F(0) = 0,   F(1) = 1
F(N) = F(N - 1) + F(N - 2), for N > 1.
Given N, calculate F(N).

Example 1:

Input: 2
Output: 1
Explanation: F(2) = F(1) + F(0) = 1 + 0 = 1.
Example 2:

Input: 3
Output: 2
Explanation: F(3) = F(2) + F(1) = 1 + 1 = 2.
Example 3:

Input: 4
Output: 3
Explanation: F(4) = F(3) + F(2) = 2 + 1 = 3.

``````public class Solution {
public int Fib(int N) {

int f1 = 0;
int f2 = 1;
int sum = 1;

if(N==0){
return f1;
}

for(int i=2;i<=N;i++){
sum=f1+f2;
f1=f2;
f2=sum;
}

return sum;
}
}``````

Time Complexity: O(n)

Space Complexity: O(1)

Contributed By: Sumit Chourasia
Contributed By: Sumit Chourasia
Contributed By: Sumit Chourasia
Contributed By: Sumit Chourasia