Merge branch 'jakwings-patch'

Author: haoel

src/anagrams/anagrams.cpp

@@ -14,16 +14,17 @@ class Solution {
 public:
     vector<string> anagrams(vector<string> &strs) {
         vector<string> result;
-        map<string, string> m;
+        map<string, int> m;
         for(int i=0; i<strs.size(); i++){
             string word = strs[i];
-            sort(word.begin(), word.end());
+            //sort it can easy to check they are anagrams or not
+            sort(word.begin(), word.end());  
             if (m.find(word)==m.end()){
-                m[word] = strs[i];
+                m[word] = i;
             }else{
-                if (m[word]!="#"){
-                    result.push_back(m[word]);
-                    m[word]="#";
+                if (m[word]>=0){
+                    result.push_back(strs[m[word]]);
+                    m[word]=-1;
                 }
                 result.push_back(strs[i]);
             }

src/distinctSubsequences/distinctSubsequences.cpp

@@ -91,12 +91,12 @@ int numDistinct1(string S, string T) {
 //=====================
 //
 //  The idea here is an optimization of above idea 
-//  (It might be difficult to understand if you don't know the above idea)
+//  (It might be difficult to understand if you don't understand the above idea)
 //
 //    For example:
 //
 //      S = "abbbc"  T="abb"
-//      posMap = { [a]={0}, [b]={1,2} }
+//      posMap = { [a]={0}, [b]={2,1} } <- the map of T's every char.
 //      numOfSubSeq = {1, 0, 0, 0 }
 //
 //      S[0] is 'a', pos is 0,  numOfSubSeq = {1, 0+1, 0, 0};

src/permutationSequence/permutationSequence.cpp

@@ -69,7 +69,9 @@ string getPermutation(int n, int k) {
         ss << num[idx];
         num.erase(num.begin()+idx);
         n--;
-        k = (k-1)%group + 1;
+        //the next k also can be caculated like this: 
+        //    k = (k-1)%group + 1; 
+        k -= group * idx;
     }
 
     return ss.str();