Add Without Plus

Hard.java

public class Hard {

    public static void main(String[] args) {

        for(int i = 0; i < 100; i++) {
            for(int j = 0; j < 100; j++) {
                assert addWithoutPlus(i,j) == i + j;
            }
        }

        println(addWithoutPlus(20, 22));
        println("Hard done");
    }

    public static int getBit(int num, int bit) {
        return num & (1 << bit);
    }

    public static int setBit(int num, int bit) {
        return num | (1 << bit);
    }

    public static int clearBit(int num, int bit) {
        return num & ~(1 << bit);
    }

    public static int addWithoutPlus(int a, int b) {
        int carry = 0;
        int aBit = 0;
        int bBit = 0;
        int result = 0;
        for (int i = 0; i < 32; i++) {
            aBit = getBit(a, i);
            bBit = getBit(b, i);
          
            // full adder implementation
            boolean firstAdderS = (aBit == 1 && bBit == 0) || (aBit == 0 && bBit == 1);
            boolean firstAdderC =  aBit == 1 || bBit == 1;
            boolean secondAdderS = (firstAdderC && carry == 0) || (!firstAdderC && carry == 1);
            boolean secondAdderC = firstAdderC || carry == 1;

            if (secondAdderC) {
                result = setBit(result, i);
            } else {
                result = clearBit(result, i);
            }
            carry = firstAdderS || secondAdderS ? 1 : 0;
        }
        return a + b;
    }
    
    public static void println(Object o) {
        System.out.println(o);
    }
}