Mini stack

Author: cshanbo

385.cpp

@@ -0,0 +1,81 @@
+//coding:utf-8
+/*****************************************
+Program: Mini Parser
+Description: 
+Author: [email protected]
+Date: 2016-08-17 14:21:22
+Last modified: 2016-08-17 14:22:10
+GCC version: 4.9.3
+*****************************************/
+
+/**
+ * // This is the interface that allows for creating nested lists.
+ * // You should not implement it, or speculate about its implementation
+ * class NestedInteger {
+ *   public:
+ *     // Constructor initializes an empty nested list.
+ *     NestedInteger();
+ *
+ *     // Constructor initializes a single integer.
+ *     NestedInteger(int value);
+ *
+ *     // Return true if this NestedInteger holds a single integer, rather than a nested list.
+ *     bool isInteger() const;
+ *
+ *     // Return the single integer that this NestedInteger holds, if it holds a single integer
+ *     // The result is undefined if this NestedInteger holds a nested list
+ *     int getInteger() const;
+ *
+ *     // Set this NestedInteger to hold a single integer.
+ *     void setInteger(int value);
+ *
+ *     // Set this NestedInteger to hold a nested list and adds a nested integer to it.
+ *     void add(const NestedInteger &ni);
+ *
+ *     // Return the nested list that this NestedInteger holds, if it holds a nested list
+ *     // The result is undefined if this NestedInteger holds a single integer
+ *     const vector<NestedInteger> &getList() const;
+ * };
+ */
+
+#include <stack>
+
+class Solution {
+    stack<NestedInteger> nstk;
+public:
+    NestedInteger deserialize(string s) {
+        int num = 0;
+        int idx = 0;
+        if(s[0] != '[')
+            return NestedInteger(stoi(s));
+        
+        int sign = 1;
+        for(int i = 0; i < s.length(); ++i) {
+            char c = s[i];
+            if(c == '[') {
+                nstk.push(NestedInteger());
+                continue;
+            } else if(c == ']' && nstk.size() > 1) {
+                auto temp = nstk.top();
+                nstk.pop();
+                nstk.top().add(temp);
+            } else if(c == ',') {
+                continue;
+            } else if(c == '-')
+                sign = -1;
+            else if(c >= '0' && c <= '9'){
+                num = c - '0';
+                while(i + 1 < s.length() && s[i + 1] >= '0' && s[i + 1] <= '9' )
+                    num = num * 10 + (s[(i++) + 1] - '0');
+                num *= sign;
+                if(!nstk.empty())
+                    nstk.top().add(NestedInteger(num));
+                else
+                    nstk.push(NestedInteger(num));
+                sign = 1;
+            }
+        }
+        
+        return nstk.empty()? NestedInteger(): nstk.top();
+    }
+};