QBasic 计算还需要净胜/负多少局才能胜率增/减1%

2014年的12月29日，写了个VBS脚本，计算还需要连胜多少把才能让自己的胜率提升1%：

这个脚本的地址在：http://my.oschina.net/Tsybius2014/blog/362078

结果后来连着输了几把，胜率掉了1%（汗）。正好昨天看了下QBasic，就用QBasic写段代码计算一下吧

我的编码环境为：编译器为Win32下的FreeBasic（版本1.00.0），IDE为FBIde（版本0.4.6r4）

这段代码计算了还需要连胜多少把才能把自己的胜率提升1%，也计算了还需要连败多少把就会让胜率降低1%

计算规则：

1）以当前玩了426局，获胜86局为例，当前的胜率是0.201878，截去小数后是20%。

2）在这个基础上，连胜4局后，玩了430局，获胜90局，胜率为0.209302，截去小数后还是20%；但在连胜5局后，玩了431局，获胜91局，胜率到达0.211137，截去小数后胜率到达21%！这个时候，就认为是连胜5局后，就可以让胜率增加1个百分点。

3）同理，计算负场时，连负4局后，玩了430局，获胜86局，胜率为0.2，即20%；连负5局后，玩了431局，获胜86局，胜率为0.199536，截去小数后，是19%，视为胜率下降一个百分点。

需要注意的几点是：

1）胜率100%的时候，再连胜多少局胜率都是100%

2）胜率99%的时候，再连胜多少局胜率都是99%

3）胜率0%的时候，再连负多少局胜率都是0%

程序代码如下：

REM 计算还需要连胜多少局才能让胜率涨一点
REM 计算还需要连败多少局才能让胜率降一点DIM GAMEPLAYED AS INTEGER 
DIM GAMEWON AS INTEGER  DIM INPUT1 AS STRING : INPUT "HOW MANY GAMES HAVE YOU PLAYED? "; INPUT1
DIM INPUT2 AS STRING : INPUT "HOW MANY GAMES HAVE YOU WON? "; INPUT2PRINTGAMEPLAYED = FIX(VAL(INPUT1))
GAMEWON = FIX(VAL(INPUT2))PRINT "GAMEPLAYED: "; GAMEPLAYED
PRINT "GAMEWON: "; GAMEWONPRINT'输入合法性校验
IF GAMEPLAYED < 0 OR GAMEWON < 0 OR GAMEPLAYED < GAMEWON THENPRINT "GAMEPLAYED MUST BIGGER-EQUAL THAN 0"PRINT "GAMEWON MUST BIGGER-EQUAL THAN 0"PRINT "GAMEPLAYED MUST BIGGER THAN GAMEWON"GOTO PRG_FINISH 
END IF'计算当前胜率
PRINT "CURRENT WINNING RATE: "; GAMEWON * 100 \ GAMEPLAYED; "%"'计数器
DIM COUNTER AS INTEGER'计算还需要多少局连胜才能增长一点胜率'检查特例
IF GAMEPLAYED = GAMEWON THENPRINT "NO NEED TO IMPROVE!"GOTO MISSION1_COMPLETE
ELSEIF GAMEWON * 100 \ GAMEPLAYED = 99 THENPRINT "NO SOLUTION TO IMPROVE!"GOTO MISSION1_COMPLETE
END IF'模拟玩一局赢一局的过程
COUNTER = 1
DO IF (GAMEWON + COUNTER - 1) * 100 \ (GAMEPLAYED + COUNTER - 1) < _(GAMEWON + COUNTER) *  100 \ (GAMEPLAYED + COUNTER) THENEXIT DOELSECOUNTER = COUNTER + 1END IF
LOOP'打印结论1
PRINT "TO IMPROVE 1% WINNING RATE, YOU NEED TO WIN"; COUNTER; " GAME(S) CONTINUOUSLY"MISSION1_COMPLETE:'计算还需要多少局连败才能降低一点胜率'检查特例
IF GAMEWON = 0 THENPRINT "WINNING PERCENTAGE: 0%"PRINT "CANNOT DECLINE ANY MORE!"GOTO MISSION2_COMPLETE
END IF'模拟玩一局输一局的过程
COUNTER = 1
DO IF (GAMEWON) * 100 \ (GAMEPLAYED + COUNTER - 1) > _(GAMEWON) *  100 \ (GAMEPLAYED + COUNTER) THENEXIT DOELSECOUNTER = COUNTER + 1END IF
LOOP'打印结论2
PRINT "TO DECLINE 1% WINNING RATE, YOU NEED TO LOSE"; COUNTER; " GAME(S) CONTINUOUSLY"MISSION2_COMPLETE:PRG_FINISH:
SLEEP
END

运行结果截图：

END