题解 | 计算某字符出现次数

#include <stdio.h>
int main() {

	int sum = 0;
	char arr[1001] = { 0 };
	char* p = arr;
	char x = 0;
	gets(arr);//输入给定字符串
	x = getchar();//索引字符
	if (x >= '0' && x <= '9')//判断是否为数字
	{
		while (*p != '\0')

		{
			if (*p == x)
			{
				sum++;
				p++;


			}
			else p++;
		}
		printf("%d", sum);
	}
	if (x >= 'A' && x <= 'z')//判断是否为字母
	{
		while (*p != '\0')
		{
			if (*p == x || *p == x + 32 || *p == x - 32)//大小写
			{
				sum++;
				p++;


			}
			else p++;
		}
		printf("%d", sum);
	}
	



	return 0;
}