题解 | #计算某字符出现次数#

#include <stdio.h>

int main()
{
    char inputBuffer[1000] = {0}, convertBuffer[1000] = {0}, key = 0;
    unsigned int inputCnt = 0, flag = 0, i  = 0, cnt = 0, keyCnt = 0;

  	/*get input string*/
    while(scanf("%c", &inputBuffer[inputCnt]) != EOF)
    {
        inputCnt++;
    }
  
  	/*input data convert, like A -> a, and get key,convert it*/
    for(i = 0; i < inputCnt; i++)
    {
        keyCnt++;
         if(inputBuffer[i] == '\n')
        {
            key = inputBuffer[i + 1];
            if((key >= 65) && (key < 90))
            {
                key += 32;
            }
            break;
        }

        if((inputBuffer[i]) >= 65 && (inputBuffer[i] <= 90))
        {
            convertBuffer[i] = inputBuffer[i] + 32;
        }
        else 
        {
            convertBuffer[i] = inputBuffer[i];
        }
    }
	/*calculate key occur count*/
    for(i = 0; i < keyCnt; i++)
    {
        if(convertBuffer[i] == key)
        {
            cnt++;
        }
    }
  
	/*printf result*/
    printf("%d\r\n", cnt);
}