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sundeshguptasundeshgupta
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2 parents d6eb8c5 + 74cc428 commit 6e10f09

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lines changed

‎arithmetic_decode.cpp

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#include <bits/stdc++.h>
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using namespace std;
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#define ll long long
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const ll MIN = 0;
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const ll MAX = 65535;
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int lower[257];
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#define err() cout<<"=================================="<<endl;
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#define errA(A) for(auto i:A) cout<<i<<" ";cout<<endl;
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#define err1(a) cout<<#a<<" "<<a<<endl
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#define err2(a,b) cout<<#a<<" "<<a<<" "<<#b<<" "<<b<<endl
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#define err3(a,b,c) cout<<#a<<" "<<a<<" "<<#b<<" "<<b<<" "<<#c<<" "<<c<<endl
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#define err4(a,b,c,d) cout<<#a<<" "<<a<<" "<<#b<<" "<<b<<" "<<#c<<" "<<c<<" "<<#d<<" "<<d<<endl
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string write_bits(bool bit, int bit_to_fall){
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string tmp;
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tmp += to_string(bit);
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while(bit_to_fall){
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tmp += to_string(!bit);
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bit_to_fall -= 1;
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}
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return tmp;
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}
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int to_int(int _pos, string &encode){
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int n = 0;
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for (int i = _pos; i < sizeof(short) * 8 + _pos; i++)
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{
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n <<= 1;
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n |= encode[i] - '0';
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}
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return n;
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}
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ll add_bit(ll value, int count_taken, bool &flag, string &encode){
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bitset<16> a(value);
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if(flag == 1){
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a.reset(0);
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}
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else if(count_taken > encode.length()){
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a.set(0);
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flag = 1;
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}
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else if(encode[count_taken] == '1'){
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a.set(0);
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}
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else if(encode[count_taken] == '0'){
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a.reset(0);
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}
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value = (ll)(a.to_ulong());
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return value;
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}
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int main(){
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const ll ONE_QTR = MAX / 4 + 1;
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const ll HALF = 2 * ONE_QTR;
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const ll THREE_QTR = 3 * ONE_QTR;
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ll len;
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string code;
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cin >> len;
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for(int i=0; i<=256; i++) cin >> lower[i];
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cin >> code;
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string decode = "";
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ll _low[len];
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ll _high[len];
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_low[0] = MIN;
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_high[0] = MAX;
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ll value = to_int(0, code);
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int count_taken = 16;
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bool flag = 0;
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for(int i=1;i<len;i++){
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ll range = (_high[i-1] - _low[i-1] + 1);
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ll nxt = (((value - _low[i-1]) + 1) * len - 1) / range;
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int symbol;
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for(symbol = 1; lower[symbol] <= nxt; symbol++);
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_low[i] = _low[i-1] + (range * lower[symbol-1]) / len;
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_high[i] = _low[i-1] + (range * lower[symbol]) / len - 1;
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if(symbol == 256)
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break;
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decode += char(symbol);
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for(;;){
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if(_high[i] >= HALF){
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if(_low[i] >= HALF){
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value -= HALF;
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_low[i] -= HALF;
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_high[i] -= HALF;
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}
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else if (_low[i] >= ONE_QTR && _high[i] < THREE_QTR)
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{
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value -= ONE_QTR;
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_low[i] -= ONE_QTR;
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_high[i] -= ONE_QTR;
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}
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else
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{
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break;
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}
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}
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_low[i] = 2 * _low[i];
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_high[i] = 2 * _high[i] + 1;
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value = add_bit(2 * value, count_taken, flag, code);
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count_taken++;
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}
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}
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cout << decode << endl;
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}

‎arithmetic_encode.cpp

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#include <bits/stdc++.h>
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using namespace std;
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#define ll long long
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const ll MIN = 0;
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const ll MAX = 65535;
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int lower[257];
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#define err() cout<<"=================================="<<endl;
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#define errA(A) for(auto i:A) cout<<i<<" ";cout<<endl;
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#define err1(a) cout<<#a<<" "<<a<<endl
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#define err2(a,b) cout<<#a<<" "<<a<<" "<<#b<<" "<<b<<endl
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#define err3(a,b,c) cout<<#a<<" "<<a<<" "<<#b<<" "<<b<<" "<<#c<<" "<<c<<endl
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#define err4(a,b,c,d) cout<<#a<<" "<<a<<" "<<#b<<" "<<b<<" "<<#c<<" "<<c<<" "<<#d<<" "<<d<<endl
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string write_bits(bool bit, int bit_to_fall){
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string tmp;
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tmp += to_string(bit);
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while(bit_to_fall){
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tmp += to_string(!bit);
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bit_to_fall -= 1;
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}
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return tmp;
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}
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int to_int(int _pos, string &encode){
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int n = 0;
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for (int i = _pos; i < sizeof(short) * 8 + _pos; i++)
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{
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n <<= 1;
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n |= encode[i] - '0';
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}
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return n;
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}
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ll add_bit(ll value, int count_taken, bool &flag, string &encode){
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bitset<16> a(value);
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if(flag == 1){
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a.reset(0);
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}
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else if(count_taken > encode.length()){
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a.set(0);
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flag = 1;
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}
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else if(encode[count_taken] == '1'){
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a.set(0);
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}
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else if(encode[count_taken] == '0'){
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a.reset(0);
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}
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value = (ll)(a.to_ulong());
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return value;
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}
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int main(){
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const ll ONE_QTR = MAX / 4 + 1;
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const ll HALF = 2 * ONE_QTR;
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const ll THREE_QTR = 3 * ONE_QTR;
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string text;
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cin >> text;
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int len = text.length() + 1;
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ll low[len];
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ll high[len];
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low[0] = MIN;
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high[0] = MAX;
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int current = 1;
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int i = 0;
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for(auto i: text){
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lower[i] += 1;
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}lower[256] = 1;
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for(int i=1; i<=256; i++){
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lower[i] += lower[i-1];
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}
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int bit_to_fall = 0;
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string code = "";
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while(i < len){
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if(i == len-1) current = 256;
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else current = text[i];
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i += 1;
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ll range = high[i-1] - low[i-1] + 1;
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low[i] = low[i-1] + (range * lower[current-1]) / len;
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high[i] = low[i-1] + (range * lower[current]) / len - 1;
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while(true){
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if(high[i] < HALF){
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code += write_bits(0, bit_to_fall);
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bit_to_fall = 0;
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}
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else if(low[i] >= HALF){
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code += write_bits(1, bit_to_fall);
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bit_to_fall = 0;
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low[i] -= HALF;
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high[i] -= HALF;
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}
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else if(low[i] >= ONE_QTR and high[i] < THREE_QTR){
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bit_to_fall += 1;
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low[i] -= ONE_QTR;
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high[i] -= ONE_QTR;
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}
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else
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break;
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low[i] = 2 * low[i];
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high[i] = 2 * high[i] + 1;
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}
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}
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ll p = low[i-1];
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for(int j=15; j>=0; j--){
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if((p & (1LL<<j))) code += '1';
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else code += '0';
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}
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cout << len << endl;
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for(int i=0; i<=256; i++)
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cout << lower[i] << endl;
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cout << code << endl;
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}
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// qhnwnkuewhsqmgbbuqcljjivswmdkqtbxixmvtrrbljptnsnfwzqfjmafadrrwsofsbcnuvqhffbsaqxwpqcaceh

‎huffman-decode.cpp renamed to ‎huffman_decode.cpp

File renamed without changes.

‎huffman-decode_image.cpp renamed to ‎huffman_decode_image.cpp

File renamed without changes.

‎huffman.cpp renamed to ‎huffman_encode.cpp

File renamed without changes.

‎huffman_image.cpp renamed to ‎huffman_encode_image.cpp

File renamed without changes.

‎improved-huffman-decode.cpp renamed to ‎improved_huffman_decode.cpp

File renamed without changes.

‎improved-huffman-decode_image.cpp renamed to ‎improved_huffman_decode_image.cpp

File renamed without changes.

‎improved-huffman.cpp renamed to ‎improved_huffman_encode.cpp

File renamed without changes.

‎improved-huffman_image.cpp renamed to ‎improved_huffman_encode_image.cpp

File renamed without changes.

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