起因是第二个测试点错了（只对了1和10），结果我就打印了结果，一个一个对，不是一样的吗？代码：

#include<iostream>
#include<string>
using namespace std;
string str1, str2;

void Out(int num){
    int per1 = 0, per2 = 0;
    for (int i = 0; i < str1.size(); i++){
	if (str1[i] == 'W') per1++;
	else per2++;
	if ((per1 >= num || per2 >= num) && abs(per1 - per2) >= 2) {
	    cout << per1 << ":" << per2 << endl;
	    per1 = 0, per2 = 0;
	}
    }
    cout << per1 << ":" << per2 << endl;
}

int main(){
    while (getline(cin,str2)){
	int pos = str2.find('E');
	if (pos == -1) str1 += str2;
	else {
	    str1 += string(str2.begin(), str2.begin() + pos);
	    break;
	}
	    str2.clear();
    }
    Out(11);
    cout << endl;
    Out(21);
    return 0;
}