1.设计自己的库(头文件函数声明在.h文件,实现在.cpp文件)
main.cpp
#include <iostream> #include"RANDOM.h" using namespace std; int main() { int c; randominit(); c=randominteger(4,6); cout<<c; return 0; }
random.h
#ifndef RANDOM_H_INCLUDED #define RANDOM_H_INCLUDED void randominit(); int randominteger(int low,int high); double randomdouble(double low,double high); #endif // RANDOM_H_INCLUDEDrandom.cpp
#include<cstdlib> #include<ctime> #include"RANDOM.h" void randominit() { srand(time(NULL));//加上这个语句,有个函数是srand(seed)随着seed的不同,能够产生不同的随机数 } int randominteger(int low,int high) { return (low+(high-low+1)*rand()/(RAND_MAX+1));//要控制结果在0~1000之间,可以使用代码 rand()%1001 } double randomdouble(double low,double high) { double d=(double)rand()/(RAND_MAX+1); return (low+(high-low+1)*d); }