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