24-语言入门-24-cigarettes

题目地址： http://acm.nyist.edu.cn/JudgeOnline/problem.php?pid=94 

 

描述
Tom has many cigarettes. We hypothesized that he has n cigarettes and smokes them
one by one keeping all the butts. Out of k > 1 butts he can roll a new cigarette.
Now，do you know how many cigarettes can Tom has?

输入
First input is a single line,it's n and stands for there are n testdata.then there are n lines ,each line contains two integer numbers giving the values of n and k.
输出
For each line of input, output one integer number on a separate line giving the maximum number of cigarettes that Peter can have.
样例输入
3
4 3
10 3
100 5
样例输出
5
14

124

 

 

代码：

 

#include <stdio.h>

//计算抽了多少支烟
//n-现有烟头数目
//k-k个烟头可以抽1支烟
static int calCigarettes(int n,int k);

int main()
{
     int readLen = 0;
     scanf("%d",&readLen);
     getchar();
    
     while(readLen > 0)
     {
          int n = 0;
          int k = 0;
          scanf("%d %d",&n,&k);
          getchar();
          printf("%d\n",calCigarettes(n,k));
         
          --readLen;
     }
    
     return 0;
}

//计算抽了多少支烟
//n-现有烟头数目
//k-k个烟头可以抽1支烟
static int calCigarettes(int n,int k)
{
     if(n<k || k<=1)
          return n;

     //已经抽了n支烟
     int result = n;
    
     do
     {
          //烟头中可以抽取k支烟
          int addCigaretCount = n / k;
          n = n % k + addCigaretCount;
          result += addCigaretCount;
     }while(n >= k);//剩余烟头和k对比，相等也需要进行
    
     return result;
}

 

 

做题时，漏掉了最初抽的香烟-n

另外判断条件也错了，漏掉了相等情况的判断

 

 

对于题目给定的测试数据测试没有问题，一直找不到问题出错在哪里，

后来借鉴 【16-语言入门-16-谁获得了最高奖学金】出错找错的经验

从输入数据入手，连续输入以下数据

 

2 3

3 3

4 3

5 3

6 3

7 3

8 3

9 3

当输入 9 3 时，发现少计算了1，最终确定了错误发生的地方。