题目大意：在给出的段落里面找出“doge”出现的次数。大写和小写都能够。
解题思路：字符串匹配问题，能够在之前将字母都转换成统一格式。
代码：
#include <stdio.h>
#include <string.h> const int N = 1e6;
char str[N];
const char *s1 = "doge"; int find () { int sum = 0;
char *p = strstr(str, s1);
while (p != NULL) { sum++;
p = p + 4;
//if (*p == '\0')
// break; p = strstr (p, s1);
}
return sum;
} int main () { int count = 0;
while (scanf ("%s", str) != EOF) { for (int i = 0; i < strlen (str); i++)
if (str[i] >= 'A' && str[i] <= 'Z')
str[i] += 32;
count += find ();
}
printf ("%d\n", count);
return 0;
}