Create Day 22 Sort Characters By Frequency.cpp

Author: tusharjaiswal123

Day 22 Sort Characters By Frequency.cpp

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+PROBLEM:
+
+
+Given a string, sort it in decreasing order based on the frequency of characters.
+
+Example 1:
+Input:
+"tree"
+
+Output:
+"eert"
+
+Explanation:
+'e' appears twice while 'r' and 't' both appear once.
+So 'e' must appear before both 'r' and 't'. Therefore "eetr" is also a valid answer.
+
+Example 2:
+Input:
+"cccaaa"
+
+Output:
+"cccaaa"
+
+Explanation:
+Both 'c' and 'a' appear three times, so "aaaccc" is also a valid answer.
+Note that "cacaca" is incorrect, as the same characters must be together.
+
+Example 3:
+Input:
+"Aabb"
+
+Output:
+"bbAa"
+
+Explanation:
+"bbaA" is also a valid answer, but "Aabb" is incorrect.
+Note that 'A' and 'a' are treated as two different characters.
+
+
+
+
+SOLUTION:
+
+
+
+unordered_map<char,int> m;
+
+class Solution {
+public:
+
+    bool static cmp(char a,char b)
+    {
+        return (m[a]>m[b] || (m[a]==m[b] && a<b));
+    }
+    
+    string frequencySort(string s) {
+        
+        int i,n;
+        n=s.length();
+        m.clear();
+        
+        for(i=0;i<n;i++)
+        {
+            m[s[i]]++;
+        }
+        
+        // for(auto k:m)
+        // {
+        //     cout<<k.first<<" "<<k.second<<endl;
+        // }
+        
+        sort(s.begin(),s.end(),cmp);
+       
+    
+        
+        return s;
+    }
+};