STL---随机数发生器

#include <iostream>  #include <stdlib.h>   //rand() srand()#include <time.h> using namespace std;//产生[low, high)之间的随机数double randval(double low, double high)  {       double val;       val = ((double)(rand()%RAND_MAX)/(double)RAND_MAX)*(high - low) + low;       return(val);   }int main(void)  {      srand(time(NULL));   //初始化随机数种子，只在程序的开头调用一次    for(int i=0; i<200; i++)        cout << randval(0, 1) << endl;    return 0;}