就是倒数读取WL那里，用if(c=='L')是可以通过的，可是改成else就不行，前面设置跳过空字符了的啊，测试案例也和答案一样的，就很奇怪

#include <iostream>
#include <algorithm>
#include <cstring>
#define MAX_N 62521
using namespace std;

char a[MAX_N];

void solve()
{   int score1 = 0, score2 = 0;
    for(int i = 0; i < strlen(a); i++) {
        if(a[i] == 'W') score1++;
        else score2++;
        if(max(score1, score2) >= 11 && abs(score1 - score2) >= 2) {
            cout<<score1<<":"<<score2<<endl;
            score1 = score2 = 0;
        }
    }
    cout<<score1<<":"<<score2<<endl;
    cout<<endl;
    score1 = score2 = 0;
    for(int i = 0; i < strlen(a); i++) {
        if(a[i] == 'W') score1++;
        else score2++;
        if(max(score1, score2) >= 21 && abs(score1 - score2) >= 2) {
            cout<<score1<<":"<<score2<<endl;
            score1 = score2 = 0;
        }
    }
    cout<<score1<<":"<<score2<<endl;
    cout<<endl;
}

int main()
{
    int i = 0;
    while(1) {
        char c = getchar();
        if(c == 'E') break;
        if(c == '\n' || c == '\t' || c == 32 || c == '\0') continue;
        if(c == 'W') a[i++] = c;
        else a[i++] = c;
    }
    solve();
    return 0;
}