Several methods of calculating the average value of two numbers

Method 1 ： Directly find the average （ Add two numbers and divide by two ）

int average(int x,int y){
    return (x + y) / 2;
}

This algorithm has some defects , When x and y When large enough x and y And there will be data overflow , So we can't get the result we want .（ It is not recommended to use ）

Method 2 ：x + y And x Divide by 2 And , Data overflow can be avoided

int average(int x,int y){
    return x + (y - x) / 2;
}

  Method 3 ： Improvement method version II （ Displacement ）

int average(int x,int y){
    return x + ((y - x) >> 1);
}

  Method four ： Using bit operations - Intersection plus half of difference （ Rounding down ）

int average(int x,int y){
    return (x & y) + ((x ^ y) >> 1);
}

  Method five ： Using bit operations -  Intersection plus half of difference （ Rounding up ）

int average(int x,int y){
    return (x | y) - ((x ^ y) >> 1);
}

Method four 、 V see link ： The magic of bit operation - Find the average of two integers - You know