Rust program to subtract a number without using the \'-\' operator

Program/Source Code:

The source code to subtract a number without using the '-' operator is given below. The given program is compiled and executed successfully.

// Rust program to subtract a number 
// without using '-' operator

use std::io;

fn main() 
{
    let mut n1:i32 = 0;
    let mut n2:i32 = 0;
    let mut sub:i32 = 0;
    
    let mut input1 = String::new();
    let mut input2 = String::new();
    
    println!("Enter number1: ");
    io::stdin().read_line(&mut input1).expect("Not a valid string");
    n1 = input1.trim().parse().expect("Not a valid number");

    println!("Enter number2: ");
    io::stdin().read_line(&mut input2).expect("Not a valid string");
    n2 = input2.trim().parse().expect("Not a valid number");

    sub = n1 + (!n2) + 1;
	
    println!("Subtraction is: {}",sub);    
}

Output:

RUN 1:
Enter number1: 
10
Enter number2: 
20
Subtraction is: -10

RUN 2:
Enter number1: 
76
Enter number2: 
53
Subtraction is: 23

Explanation:

Here, we read the value of n1, n2 from the user. Then we subtracted n2 from n1 using the '!' operator and printed the result.