代码在本地跑测试点2正确，但在线IDE中答案就不对了，有没有大佬帮看一下怎么回事

代码奉上：

s = ''

while(s.find('E') == -1):
    s += input()
        
def countGrade(record, mode):    
    grade = []

    i = 1
    win_count = 0
    idx = 0
    while(record[idx] != 'E'):
        if record[idx] == 'W':
            win_count += 1
        
        if (win_count >= mode or i - win_count >= mode) and abs(2*win_count - i) >= 2:         
            grade.append('%d:%d' % (win_count, i-win_count))
            i = 0
            win_count = 0
            
        i += 1
        idx += 1
        
    if i-1>0:
        grade.append('%d:%d' % (win_count, i-win_count-1))
    elif idx == 0:
        grade.append('0:0')
        
    return grade

grade_11 = countGrade(s, 11)
for i in grade_11:
    print(i)
print()

grade_21 = countGrade(s, 21)
for j in grade_21:
    print(j)