生成不重复的随机数对（C/C++）

 1 #include <stdio.h>
#include <algorithm>
#include <stdlib.h>
#include <time.h>
using namespace std;
const int max_rand = 2001;
int a[max_rand], b[max_rand];
struct node
{
    int x, y;
    bool operator < (const node q) const
    {
        if(x == q.x)
            return y < q.y;
        return x < q.x;
    }
}RAND[20010];

int main()
{
    for (int i = 0; i < max_rand; i ++)
        a[i] = b[i] = i;
    b[0] = -1;
    int aa = 2, bb = 10;
//    time_t t;
//    srand((unsigned) time(&t));
    srand((unsigned)time(NULL));//    let the seed accroding to time
    for (int i = 0; i < 2000; i ++)
    {
        int x = rand()%2001; //make x between 0 and 2000(include)
        int y = rand()%2001; //same up;
/*        double text = (double)rand()/RAND_MAX*(bb-aa) +aa; //produce double text between aa and bb
        printf ("%f
", text);
        getchar();
*/
        if((!x || !y)||(!a[x] && b[y] == -1))
        {
            i --;
            continue;
        }
        RAND[i] = (node){x, y};

        a[x] = 0;
        b[y] = -1;
    }
    sort(RAND, RAND +2000);
    for (int i = 0; i < 2000; i ++)
    {
        printf("%d %d
", RAND[i].x, RAND[i].y);
 //     getchar();
    }
    return 0;
}