Merge branch 'master' of github.com:doocs/leetcode

Author: yanglbme

solution/001.Two Sum/Solution.js

@@ -0,0 +1,11 @@
+const twoSum = function(nums, target) {
+  const map = {};
+
+  for (let i = 0; i < nums.length; i++) {
+    if (map[nums[i]] !== undefined) {
+      return [map[nums[i]], i]
+    } else {
+      map[target - nums[i]] = i
+    }
+  }  
+};

solution/004.Median of Two Sorted Arrays/Solution.cpp

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+class Solution {
+public:
+	double findMedianSortedArrays(vector<int>& nums1, vector<int>& nums2) {
+		int nums[10000] = { 0 };
+		int index = 0;
+		vector<int>::iterator it1 = nums1.begin();
+		vector<int>::iterator it2 = nums2.begin();
+		for (; it1 != nums1.end() && it2 != nums2.end();) {
+			if (*it1 >= *it2) {
+				nums[index++] = *it2;
+				it2++;
+			}
+			else {
+				nums[index++] = *it1;
+				it1++;
+			}
+		}
+		
+		while (it1 != nums1.end()) {
+			nums[index++] = *it1;
+			it1++;
+		}
+		while (it2 != nums2.end()) {
+			nums[index++] = *it2;
+			it2++;
+		}
+
+		if (index % 2 == 0) {
+			return (double)((nums[index/2] + nums[index/2 - 1])/2.0);
+		}
+		else {
+			return (double)(nums[index/2]);
+		}
+
+	}
+};

solution/007.Reverse Integer/Solution.js

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+const reverse1 = function(x){
+  let s = String(x);
+  let isNegative = false;
+  if(s[0] === '-'){
+    isNegative = true;
+  }
+  s = parseInt(s.split('').reverse().join(''));
+  return isNegative ? (s > Math.pow(2,31) ? 0 : -s) : (s > Math.pow(2,31) - 1 ? 0 : s);
+}
+
+const reverse = function(x){
+  let result = parseInt(x.toString().split('').reverse().join(''));
+  if(result > Math.pow(2,31) - 1 || -result < Math.pow(-2,31)) return 0;
+  return x > 0 ? result: -result;
+}

solution/013.Roman to Integer/Solution2.py

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+class Solution(object):
+    def romanToInt(self, s):
+        dict = {'M':1000, 'D':500, 'C':100, 'L':50, 'X':10, 'V':5, 'I':1}   #对应关系存在一个字典里
+        sum = 0
+        for i in range(len(s)-1):
+            if dict[s[i]] < dict[s[i+1]]:   #这里小于是因为只会有一个减的存在，换句话说如果两个一样的出现，应该是加法
+                sum -= dict[s[i]]
+            else:
+                sum += dict[s[i]]
+        return sum+dict[s[-1]]   #最后一位一定是加

solution/014.Longest Common Prefix/Solution.js

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+const longestCommonPrefix = function(strs){
+  if(strs.length === 0) return '';
+  for(let j = 0; j < strs[0].length; j++){
+    for(let i = 0; i < strs.length; i++){
+      if(strs[0][j] !== strs[i][j]){
+        return strs[0].substring(0,j);
+      }
+    }
+  }
+  return strs[0];
+}