huffman coding

Author: namanjain0501

HuffmanCoding/huffman_coding.cpp

@@ -0,0 +1,253 @@
+#include <bits/stdc++.h>
+#include <stdio.h>
+#include <stdlib.h>
+using namespace std;
+
+ifstream input;
+ofstream output;
+
+struct Node{
+	char *symbol;
+	int frequency;
+	Node *next;
+	Node *left;
+	Node *right;
+};
+
+void TreeTraverse(string *H,Node *A,string C)
+{
+	output<<A->symbol<<" ";
+	if(A->left == NULL && A->right==NULL)
+	{
+		if(*(A->symbol) >= 'a' && *(A->symbol)<='z')
+		{
+			H[(int)(*(A->symbol) - 'a')] = C;
+		}
+		else
+		{
+			H[(int)(*(A->symbol)-'0')+26] = C;
+		}
+	}
+	else
+	{
+		string t;
+		t = C;
+		C.append("0");
+		t.append("1");
+		TreeTraverse(H,A->left,C);
+		TreeTraverse(H,A->right,t);
+	}
+}
+
+int main()
+{
+	
+	input.open("log.txt");
+	output.open("18CS10034_A5_output.txt");
+
+	int n;
+	input>>n;
+	int freq[36];
+
+	for(int i=0;i<36;i++)
+	{
+		freq[i]=0;
+	}
+
+	for(int i=0;i<n;i++)
+	{
+		string s;
+		getline(input,s);
+
+		for(int j=0;j<s.size();j++)
+		{
+			if((int)s[j] >='a' && (int)s[j] <='z')
+			{
+				freq[(int)s[j] - 'a']++;
+			}
+			else
+			{
+				freq[(int)s[j] - '0' + 26]++;
+			}
+		}
+	}
+
+	for(int i=0;i<36;i++)
+	{
+		if(i==0)
+		{
+			output<<(char)('a'+i)<<"="<<freq[i];
+		}
+		else if(i<=25)
+		{
+			output<<","<<(char)('a'+i)<<"="<<freq[i];
+		}
+		else
+		{
+			output<<","<<(char)('0'+i-26)<<"="<<freq[i];
+		}
+	}
+	output<<"\n";
+
+	int temp[36];
+	for(int i=0;i<36;i++)
+		temp[i] = freq[i];
+	int max=INT_MIN;
+	int index;
+
+	Node *list;
+	list = NULL;
+
+	for(int i=0;i<36;i++)
+	{
+		max = INT_MIN;
+		for(int j=0;j<36;j++)
+		{
+			if(temp[j]>=max)
+			{
+				max = temp[j];
+				index = j;
+			}
+		}
+
+		char *s;
+		s = new char;
+		if(index>=0 && index<=25)
+		{
+			*s = char(index + 'a');
+		}
+		else
+			*s = char(index + '0' -26);
+
+		Node *tem;
+		tem = new Node;
+		tem->frequency = max;
+		tem->symbol = s;
+		tem->left = NULL;
+		tem->right = NULL;
+		tem->next = NULL;
+
+		temp[index] = INT_MIN;
+
+		if(list == NULL)
+		{
+			list = tem;
+		}
+		else
+		{
+			tem->next = list;
+			list = tem;
+		}
+
+	}
+
+	int count=1;
+
+	while(list->next !=NULL)
+	{
+
+		Node *tr;
+		tr = list;
+		while(tr!=NULL)
+		{
+			cout<<tr->symbol<<" ";
+			tr = tr->next;
+		}
+		cout<<endl;
+
+
+		char *a;
+		if(count>9)
+		{
+			a = new char[3];
+			a[0] = 'N';
+			a[1] = (count/10) + '0';
+			a[2] = (count%10) + '0';
+		}
+		else
+		{
+			a = new char[2];
+			a[0] = 'N';
+			a[1] = count + '0';
+		}
+
+		Node *temp;
+		temp = new Node;
+		temp->symbol = a;
+		temp->frequency = list->frequency + list->next->frequency;
+		temp->left = list;
+		temp->right = list->next;
+		temp->next = NULL;
+
+		cout<<"a"<<endl;
+		list = list->next->next;
+		if(list == NULL)
+		{
+			list = temp;
+			break;
+		}
+
+
+		Node *temp1;
+		temp1 = list;
+
+		if(list->frequency >= temp->frequency)
+		{
+			temp->next = list;
+			list = temp;
+		}
+		else
+		{
+			while(list->next!=NULL)
+			{
+				if(list->next->frequency >= temp->frequency)
+				{
+					temp->next = list->next;
+					list->next = temp;
+					break;
+				}
+				list = list->next;
+			}
+			if(list->next==NULL)
+			{
+				list->next = temp;
+			}
+			list = temp1;
+
+		}
+
+		count++;
+
+	}
+
+	cout<<list->symbol<<endl;
+
+	string H[36];
+	string C = "";
+
+	TreeTraverse(H,list,C);
+
+	output<<"\n";
+
+	for(int i=0;i<36;i++)
+	{
+		cout<<H[i]<<endl;
+	}
+	
+	for(int i=0;i<36;i++)
+	{
+		if(i<=25)
+		{
+			output<<(char)('a'+i)<<" "<<H[i]<<endl;
+		}
+		else
+		{
+			output<<(char)('0'+i-26)<<" "<<H[i]<<endl;
+		}
+	}
+
+
+
+
+
+}