getprice

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <time.h>


int GetPrice(int old_prince)
{
    int new_price,rand_data;
    //初始化一个随机数种子
    srand((int)time(0));
    //产生一个0-99的一个随机数
    rand_data = (int) (rand()*100.0/RAND_MAX);
    //概率性涨价变化
    if(rand_data < 85) new_price = old_prince -10;
    else new_price = old_prince;
    return new_price;
}

int main(void)
{
    printf("old_price=32,new_prince=%d\n",GetPrice(32));
    sleep(1);
    printf("old_price=36,new_prince=%d\n",GetPrice(36));
    sleep(2);
    printf("old_price=39,new_prince=%d\n",GetPrice(39));
    sleep(1);
    printf("old_price=67,new_prince=%d\n",GetPrice(67));
}
/*
 *执行结果
old_price=32,new_prince=22
old_price=36,new_prince=36
old_price=39,new_prince=29
old_price=67,new_prince=57
*/