main.cpp
#include <iostream> #include <fstream> using namespace std; int main() { fstream in;//文件读入流 in.open("k:\\file1.txt", ios::in | ios::_Nocreate);//以读入不创建模式打开,即如果不存在则打开失败 if (!in) { cout << "打开失败" << endl; return -1; } char ch1 = 0, ch2 = 0;//前一个字符,后一个字符 unsigned int number = 0;//is的个数 while (in.get(ch2)) { if (ch1 == 'i'&&ch2 == 's')//如果前一个字符为i,后一个字符为s { number++; } ch1 = ch2;//后一个传到前一个 } cout << number << endl; in.close(); system("pause"); return 0; }
file1.txt
is that ture? ok,that is ture so what? ok,ok.that i //此处的is中间夹了一个换行,所以不算一个is单词 s so bad.
运行结果: