Computing INT_MAX and INT_MIN with Bitwise operations - GeeksforGeeks

30 Apr, 2021
Prerequisites : INT_MAX and INT_MIN in C/C++ and Applications. Arithmetic shift vs Logical shiftSuppose you have a 32-bit system : The INT_MAX would be 01111111111111111111111111111111 and INT_MIN would be 10000000000000000000000000000000. 0 & 1 in most-significant bit position representing the sign bit respectively.Computing INT_MAX and INT_MIN In C/C++ : The number 0 is represented as 000...000(32 times).  
We compute the NOT of 0 to get a number with 32 1s. This number is not equal to INT_MAX because the sign bit is 1, i.e. negative number.
Now, a right shift of this number will produce 011...111 which is INT_MAX.
INT_MIN is NOT of INT_MAX.
Note : 0 should be taken as unsigned int.Reason : If 0 is signed, during Step 2, right shift of 111..111 will yield 111...111. This is because arithmetic right shift preserves the sign of the number. In Java, we have the feature of logical right shift available to us.   
C++
Java
Javascript
// CPP code to compute INT_MAX and INT_MIN using// bitwise operations#include <bits/stdc++.h>using namespace std; void printMinMaxValues(){    // 0 saved as unsigned int    unsigned int max = 0;     // Computing NOT of 0    max = ~max;         // 1 time arithmetic right shift    max = max >> 1;         // Computing INT_MIN    int min = max;         // INT_MIN = ~INT_MAX    min = ~min;         // Printing the result    cout << "INT_MAX : " << max        << " INT_MIN : " << min;} // Driver codeint main(){    printMinMaxValues();    return 0;}
// Java code to compute INT_MAX and INT_MIN using// bitwise operationspublic class Solution{    static void printMinMaxValues()    {        int max = 0;             // Computing NOT of 0        max = ~max;         // 1 time logical right shift for INT_MAX        max = max >>> 1;                 // Computing INT_MIN        int min = max;                 // INT_MIN = ~INT_MAX        min = ~max;             // Printing the result        System.out.println("INT_MAX " + max +                           " INT_MIN " + min);    }     public static void main(String[] args)    {        printMinMaxValues();    }}
<script> // Javascript code to compute INT_MAX and INT_MIN using// bitwise operations     function printMinMaxValues()    {        let max = 0;               // Computing NOT of 0        max = ~max;           // 1 time logical right shift for INT_MAX        max = max >>> 1;                   // Computing INT_MIN        let min = max;                   // INT_MIN = ~INT_MAX        min = ~max;               // Printing the result        document.write("INT_MAX - " + max +                           ", INT_MIN " + min);    }     // driver program             printMinMaxValues(); // This code is contributed by code_hunt.</script>
Output:  
INT_MAX 2147483647 INT_MIN -2147483648
Asked in : Google This article is contributed by Rohit Thapliyal. If you like GeeksforGeeks and would like to contribute, you can also write an article using write.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above. 
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