Create Check-if-at-least-two-out-of-three-booleans-are-true.md

Author: tangculijier

Check-if-at-least-two-out-of-three-booleans-are-true.md

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+给3个布尔变量，当其中有2个或者2个以上为true菜返回true
+===
+问题
+给3个boolean变量，a,b,c，当其中有2个或2个以上为true时才返回true？
+最笨的方法：
+```java
+boolean atLeastTwo(boolean a, boolean b, boolean c) 
+{
+    if ((a && b) || (b && c) || (a && c)) 
+    {
+        return true;
+    }
+    else
+    {
+        return false;
+    }
+}
+```
+* 优雅解法1
+```java
+    return a ? (b || c) : (b && c);
+```
+
+* 优雅解法2
+```java
+    return (a==b) ? a : c;
+```
+
+* 优雅解法3
+```java
+   return a ^ b ? c : a
+```
+
+* 优雅解法4
+```java
+    return a ? (b || c) : (b && c);
+```
+
+stackoverflow链接： http://stackoverflow.com/questions/3076078/check-if-at-least-two-out-of-three-booleans-are-true