再次与随机问题

Question

请看看下面的代码

#include <iostream> 
#include <stdlib.h> 
#include <ctime> 

using namespace std; 

int main() 
{ 
    enum Movement{STAND=1,WALK,RUN,CRAWL}; 

    srand(time(0)); 
    Movement state = (Movement)(1+rand()%4); 

    for(int i=0;i<10;i++) 
    { 

    cout << state << endl; 

    switch(state) 
    { 
     /*Here the logic is, 
     * 
     * 1. From stand, he can walk or crawl 
      2. From Walk, he can stand or run 
      3. From Run, he can walk 
      4. From Crawl, he can stand 
     */ 

     case STAND: 
      cout << "You can walk or crawl" << endl;   
      while(state==WALK || state==CRAWL) 
      { 
       state = (Movement)(1+rand()%4); 
      } 
      break; 


     case WALK: 
      cout << "You can stand or run" << endl; 
      while(state==STAND || state==RUN) 
      { 
       state = (Movement)(1+rand()%4); 
      } 
      break; 


     case RUN: 
      cout << "You can walk" << endl; 
      while(state==WALK) 
      { 
       state = (Movement)(1+rand()%4); 
      } 
      break; 

     default: 
      cout << "You can stand" << endl; 
      while(state==STAND) 
      { 
       state = (Movement)(1+rand()%4); 
      } 

    } 

    } 
} 

我使用随机的，并基于这些给定条件期望随机结果。但是我得到的结果如下。

2 
You can stand or run 
2 
You can stand or run 
2 
You can stand or run 
2 
You can stand or run 
2 
You can stand or run 
2 
You can stand or run 
2 
You can stand or run 
2 
You can stand or run 
2 
You can stand or run 
2 
You can stand or run 

这是为什么？我已经尝试过do..while循环。一点都不好。没有什么是检查我在病例陈述中给出的条件。请帮忙。

Answer 1

翻转你的while循环来做，而。表达式是无效的，以及为检查（除非它是你的意图，他们不匹配的文本）。各州，根据消息是：

Stand ==> (Walk || Crawl) 
Walk ==> (Stand || Run) 
Run ==> (Walk) 
Crawl ==> (Stand) 

所以需要改变，以

1. 的部分生成新的随机数之前检查它。和..
2. 不离开，直到达到一个有效的生产。

后半部分是运行和抓取状态非常重要的。因为他们只能生产一种有效的结果状态，纺兰特（）调用寻找一个价值是没有意义的。只需设置新的状态并再次循环。

关于上述（2）：

case WALK: 
     cout << "You can stand or run" << endl; 
     while(state==STAND || state==RUN) 
     { 
      state = (Movement)(1+rand()%4); 
     } 
     break; 

变为...

case WALK: 
     cout << "You can stand or run" << endl; 
     do { 
      state = (Movement)(1+rand()%4); 
     } while(state!=STAND && state!=RUN); 
     break; 

关于运行和抓取规定：

case RUN: 
     cout << "You can walk" << endl; 
     state = WALK; 
     break; 

    default: // CRAWL 
     cout << "You can stand" << endl; 
     state = STAND; 
     break; 

这让你多一个检查自己，我给你留下。与恒种子Ç

Answer 2

rand（）函数总是倾向于给予相同的“随机”值，不管你做什么。

更好的方法是写自己的RandomGenerator功能并用其

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

int RandomGenerator(int min, int max) // Generate min < random int < max 
{ 
    int randNum; 
    srand(rand()*time(NULL)); 
    randNum = rand() % max + min; 
    // printf(" Random number is %d \n", randNum); 
    return randNum; 
} 

而且移动你的Movement state = (Movement)(1+rand()%4);内for环

Answer 3

解决方案：移动Movement state = (Movement)(1+rand()%4);到for循环。

更正代码：

#include <iostream> 
#include <stdlib.h> 
#include <ctime> 

using namespace std; 

int main() 
{ 
    enum Movement{STAND=1,WALK,RUN,CRAWL}; 
    srand(time(0)); 

    for(int i=0;i<10;i++) 
    { 

     Movement state = (Movement)(1+rand()%4); 

     cout << state << endl; 

     switch(state) 
     { 
      /*Here the logic is, 
      * 
      * 1. From stand, he can walk or crawl 
       2. From Walk, he can stand or run 
       3. From Run, he can walk 
       4. From Crawl, he can stand 
      */ 

      case STAND: 
       cout << "You can walk or crawl" << endl;   
       while(state==WALK || state==CRAWL) 
       { 
        state = (Movement)(1+rand()%4); 
       } 
       break; 


      case WALK: 
       cout << "You can stand or run" << endl; 
       while(state==STAND || state==RUN) 
       { 
        state = (Movement)(1+rand()%4); 
       } 
       break; 


      case RUN: 
       cout << "You can walk" << endl; 
       while(state==WALK) 
       { 
        state = (Movement)(1+rand()%4); 
       } 
       break; 

      default: 
       cout << "You can stand" << endl; 
       while(state==STAND) 
       { 
        state = (Movement)(1+rand()%4); 
       } 

     } 

    } 

    return 0; 
} 

输出：

3 
You can walk 
1 
You can walk or crawl 
2 
You can stand or run 
1 
You can walk or crawl 
2 
You can stand or run 
3 
You can walk 
4 
You can stand 
2 
You can stand or run 
2 
You can stand or run 
4 
You can stand 

Press any key to continue 

Answer 4

你也可以计算出你的状态机这样的下一个步骤：

... 

case STAND: 
    cout << "You can walk or crawl" << endl; 
    state = rand()%2 ? WALK : CRAWL; 
    break; 

...