while(br ==0f br为0表示括号对消完,出循环 if(ch=='()br++; else if(ch==")')br- cin >>clwhile ( br == 0 ){ //br 为 0 表示括号对消完, 出循环 cin >> ch; if ( ch == ‘(’ ) br++; else if ( ch == ‘)’ ) br--; } } } cin >> ch; } }