int main()
{
int a, b;
scanf("%d %d", &a, &b);
printf("%d\n", aplusb(a, b));
return 0;
}
int aplusb(int a, int b)
{
if (b == 0)
return a;
int sum = a ^ b; //a 和 b 二进制各位相加, 不考虑进位, 使用异或运算
int carry = (a & b) << 1; //a 和 b 二进制各位相加的进位情况
aplusb(sum, carry); //递归相加直到进位为0
}
int main()
{
int a = 4;
int b = 20;
printf("please input a & b: ");
scanf("%d %d", &a , &b);
printf("a=%d, b=%d, a+b=%d\n", a, b, aplusb(a, b));
return 0;
}
/*
* @param a: The first integer
* @param b: The second integer
* @return: The sum of a and b
*/
int aplusb(int a, int b) {
// write your code here, try to do it without arithmetic operators.
if (b == 0)
{
return a;
}
else {
int c = a ^ b;
int carry = (a & b) << 1;
return aplusb(c,carry);
}
}
/*
* @param a: The first integer
* @param b: The second integer
* @return: The sum of a and b
*/
int aplusb(int a, int b) {
if (b == 0) {
return a;
}
return aplusb(a ^ b, (a & b) << 1);
}
