56 lines
1.0 KiB
C++
56 lines
1.0 KiB
C++
#include <iostream>
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using namespace std;
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// function starts
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bool isPowerOfTwo(const int n)
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{
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// declare a variable to know if n is a power of 2 or not
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long i = 1;
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// at every iteration it will calcalute power of 2 starting from 1
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while (i < n)
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{
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i = i * 2;
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}
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// if n is the power of 2, i and n value will be same
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// if they are same, it will return true, else it will return false
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return i == n;
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}
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// Binary Method to check number is in power of two or not.
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// Time Complexity of this method is O(1)
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bool ispoweroftwo(const int n)
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{
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// if number is in power of two it will give 0, otherwise it will not zero.
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return n != 0 && (n & (n - 1)) == 0;
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}
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// main starts
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int main()
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{
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int n;
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cin >> n;
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cout << isPowerOfTwo(n) << endl;
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// Check using Binary Method
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cout << ispoweroftwo(n) << endl;
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return 0;
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}
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/*
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Example 1:
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Input: n = 1
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Output:1 (true)
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Explanation: 2^0 = 1
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Example 2:
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Input: n = 16
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Output:1 (true)
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Explanation: 2^4 = 16
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Example 3:
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Input: n = 3
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Output: 0 (false)
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*/
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