add 算法

Author: LockGit

README.md

@@ -54,6 +54,38 @@ Sorry, The item not in file dict
 如果查找到了返回一个list，list中item类型为tuple, 并且包含了在树中匹配的起,终点位置index
 ```
 
+### calc24.py 算24游戏小程序
+```
+游戏规则：给定4个数，可以执行的运算有 + - * / , 求出算的结果是24的算法过程
+
+get help：
+➜  Py git:(master) ✗ py calc24.py -h
+Usage: usage -n 1,2,3,4
+
+Options:
+  -h, --help  show this help message and exit
+  -n NUMS     specify num list
+  
+exp:
+➜  Py git:(master) ✗ py calc24.py -n 10,8,9,4
+[10, 8, 9, 4]
+9 - 10 = -1
+4 + -1 = 3
+8 * 3 = 24
+Success
+
+or random test:
+➜  Py git:(master) ✗ py calc24.py
+[9, 10, 3, 6]
+10 - 9 = 1
+3 + 1 = 4
+6 * 4 = 24
+Success
+
+~~~python轮子很强大~~~
+```
+
+
 ### dispatch.py 轮转队列
 ```
 你的手头上会有多个任务，每个任务耗时很长，而你又不想同步处理，而是希望能像多线程一样交替执行。

calc24.py

@@ -0,0 +1,90 @@
+# -*- coding: utf-8 -*-
+# @Author: lock
+# @Date:   2017-06-09 22:48:14
+# @Last Modified by:   lock
+# @Last Modified time: 2017-06-10 01:48:16
+# -*- coding: utf-8 -*-
+import optparse
+import itertools
+import random
+
+
+# 洗牌
+def shuffle(n, m=-1):
+    if m == -1:
+        m = n
+    l = range(n)
+    for i in range(len(l) - 1):
+        x = random.randint(i, len(l) - 1)
+        l[x], l[i] = l[i], l[x]
+        if i == m - 1:
+            break
+    return [l[idx] for idx in range(n) if idx >= 0 and idx < m]
+
+
+# 生成4张牌
+def Get4Card():
+    card = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 10, 10, 10] * 4
+    cardidxs = shuffle(52, 4)
+    return [card[idx] for idx in cardidxs]
+
+
+def GenAllExpr(card_4, ops_iter):
+    try:
+        while True:
+            l = list(ops_iter.next()) + card_4
+            its = itertools.permutations(l, len(l))
+            try:
+                while True:
+                    yield its.next()
+            except StopIteration:
+                pass
+    except StopIteration:
+        pass
+
+
+def CalcRes(expr, isprint=False):
+    opmap = {'+': lambda a, b: a + b, '-': lambda a, b: a - b, '*': lambda a, b: a * b,
+             '/': lambda a, b: a / (b + 0.0)}
+    expr_stack = []
+    while expr:
+        t = expr.pop(0)
+        if type(t) == int:
+            expr_stack.append(t)
+        else:
+            if len(expr_stack) < 2:
+                return False
+            else:
+                a = expr_stack.pop()
+                b = expr_stack.pop()
+                if isprint:
+                    print a, t, b, '=', opmap[t](a, b)
+                try:
+                    expr_stack.append(opmap[t](a, b))
+                except ZeroDivisionError:
+                    return False
+    return expr_stack[0]
+
+
+if __name__ == "__main__":
+    parser = optparse.OptionParser('usage -n 1,2,3,4')
+    parser.add_option('-n', dest='nums', type='string', help='specify num list')
+    (options, args) = parser.parse_args()
+    nums = options.nums
+    if nums is None:
+        input_card = Get4Card()
+    else:
+        input_card = [int(x) for x in nums.split(',')]
+    card = input_card
+    if len(input_card) != 4:
+        print(parser.usage)
+        exit(0)
+    print card
+    ops = itertools.combinations_with_replacement('+-*/', 3)  # 一个24点的计算公式可以表达成3个操作符的形式
+    allexpr = GenAllExpr(card, ops)  # 数和操作符混合，得到所有可能序列
+    for expr in allexpr:
+        res = CalcRes(list(expr))
+        if res and res == 24:
+            CalcRes(list(expr), True)  # 输出计算过程
+            print "Success"
+            break