【编程之美】2.12快速寻找满足条件的两个数

/*
start time = 16:57
end time = 17:15
*/
#include <iostream>
#include <stdlib.h>
using namespace std;

//由小到大排
int cmp(const void * a, const void * b)
{
    return *((int *)a) - *((int *)b);
}
bool get_TwoNumber(int * a, int len, int sum)
{
    int i, j;
    qsort(a, len, sizeof(a[0]), cmp);
    for(i = 0, j = len - 1; i < j;)
    {
        if(a[i] + a[j] == sum)
        {
            cout << a[i] << " + " << a[j] << " = "<< sum << endl;
            return true;
        }
        else if(a[i] + a[j] < sum)
        {
            i++;
        }
        else
        {
            j--;
        }
    }
    cout << "no vaild num!" << endl;
    return false;
}

int main()
{
    int a[10] = {5,6,1,4,7,9,8};
    get_TwoNumber(a, 7, 10);
    return 0;
}