产生不同的随机数howoldareyougg的博客-

#include<stdio.h> #include<stdlib.h> #include<time.h> void Sort(int *p,int len); int main() { int a[1000]={0}; int b[100]; int i=0; int j=0; int k; int temp; char filename[20]="cfile5.txt";     FILE *fp;     clock_t start,finish;     fp=fopen(filename,"a"); srand((unsigned)time(NULL));     start=clock(); while(j<100){         temp=rand()%1000; //产生0-999的随机数，对应数组a的下标 if(a[temp]==0){             a[temp]=1;             b[j]=temp+1;             j++; } } fputc('n',fp); fprintf(fp,"Before sorting:n"); int count=0; for(k=0;k<100;k++){ if(k%10==0){ fprintf(fp,"%-3d",b[k]); } else{ fprintf(fp," %-3d",b[k]); }         count++; if(count%10==0){ fputc('n',fp); } } Sort(b,100); fprintf(fp,"After sorting:n");     count=0; for(k=0;k<100;k++){ if(k%10==0){ fprintf(fp,"%-3d",b[k]); } else{ fprintf(fp," %-3d",b[k]); }         count++; if(count%10==0){ fputc('n',fp); } }     finish=clock(); fprintf(fp,"time used %g second.",(double)(start-finish)/CLOCKS_PER_SEC); //执行时间太短了，哈哈 fclose(fp); return 0; } void Sort(int *p,int len) { int i; int j; int temp; for(i=0;i<len;i++){ for(j=i+1;j<len;j++){ if(p[i]>p[j]){                 temp=p[j];                 p[j]=p[i];                 p[i]=temp; } } } } 

运行结果：