Homework New
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e2hang
140
Exercise/Homework5/Huffman.cpp
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140
Exercise/Homework5/Huffman.cpp
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#include <bits/stdc++.h>
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using namespace std;
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struct Node {
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char ch; // <20><><EFBFBD>ڷ<EFBFBD>Ҷ<EFBFBD>ڵ㣬ch = 0
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int freq;
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bool isLeaf;
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int firstPos; // <20><><EFBFBD>ı<EFBFBD><C4B1><EFBFBD><EFBFBD>״γ<D7B4><CEB3>ֵ<EFBFBD>λ<EFBFBD>ã<EFBFBD><C3A3><EFBFBD><EFBFBD><EFBFBD> tie-break<61><6B>
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Node *left, *right;
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int createOrder; // <20><><EFBFBD><EFBFBD>˳<EFBFBD><CBB3><EFBFBD><EFBFBD><EFBFBD>ţ<EFBFBD><C5A3><EFBFBD><EFBFBD>ڷǵ<DAB7><C7B5>ڵ<EFBFBD><DAB5>Ƚ<EFBFBD>
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Node(char c, int f, int pos, int order)
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: ch(c), freq(f), isLeaf(true), firstPos(pos),
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left(NULL), right(NULL), createOrder(order) {}
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Node(Node* l, Node* r, int f, int order)
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: ch(0), freq(f), isLeaf(false), firstPos(INT_MAX),
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left(l), right(r), createOrder(order) {}
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};
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/*
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<20><><EFBFBD>ȶ<EFBFBD><C8B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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1. ȨֵС<D6B5><D0A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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2. Ȩֵ<C8A8><D6B5><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1>
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a. <20><><EFBFBD>ڵ<EFBFBD><DAB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڷǵ<DAB7><C7B5>ڵ<EFBFBD>
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b. <20><><EFBFBD><EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD>ڵ<EFBFBD> <20><> <20><> firstPos С<><D0A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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c. <20><><EFBFBD><EFBFBD>Ϊ<EFBFBD>ǵ<EFBFBD><C7B5>ڵ<EFBFBD> <20><> <20><> createOrder С<><D0A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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*/
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struct Cmp {
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bool operator()(Node* a, Node* b) {
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if (a->freq != b->freq) return a->freq > b->freq;
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// freq <20><>ͬ
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if (a->isLeaf != b->isLeaf) return a->isLeaf < b->isLeaf;
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if (a->isLeaf) return a->firstPos > b->firstPos;
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return a->createOrder > b->createOrder;
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}
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};
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unordered_map<char, string> codeMap;
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// <20><><EFBFBD>ɹ<EFBFBD><C9B9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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void dfs(Node* root, string path) {
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if (!root) return;
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if (root->isLeaf) {
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codeMap[root->ch] = path;
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return;
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}
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dfs(root->left, path + "0");
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dfs(root->right, path + "1");
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}
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// <20>ù<EFBFBD><C3B9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƴ<EFBFBD>
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string decode(Node* root, const string& s) {
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string result;
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Node* cur = root;
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for (char c : s) {
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if (c == '0') cur = cur->left;
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else if (c == '1') cur = cur->right;
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else return "INVALID";
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if (!cur) return "INVALID";
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if (cur->isLeaf) {
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result.push_back(cur->ch);
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cur = root;
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}
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}
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if (cur != root) return "INVALID"; // δ<><CEB4>Ҷ<EFBFBD>ڵ<EFBFBD><DAB5><EFBFBD><EFBFBD><EFBFBD>
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return result;
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}
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int main() {
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ios::sync_with_stdio(false);
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cin.tie(NULL);
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string text, code1, code2;
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cin >> text >> code1 >> code2;
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// ͳ<>Ƴ<EFBFBD><C6B3>ִ<EFBFBD><D6B4><EFBFBD> & <20>״γ<D7B4><CEB3><EFBFBD>λ<EFBFBD><CEBB>
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unordered_map<char, int> freq, firstPos;
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for (int i = 0; i < text.size(); i++) {
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char c = text[i];
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freq[c]++;
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if (!firstPos.count(c)) firstPos[c] = i;
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}
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// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȶ<EFBFBD><C8B6><EFBFBD>
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priority_queue<Node*, vector<Node*>, Cmp> pq;
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int createId = 0;
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for (auto& p : freq) {
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char c = p.first;
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int f = p.second;
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pq.push(new Node(c, f, firstPos[c], createId++));
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}
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// <20><><EFBFBD><EFBFBD>Ψһ<CEA8><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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while (pq.size() > 1) {
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Node* a = pq.top(); pq.pop();
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Node* b = pq.top(); pq.pop();
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Node* parent = new Node(a, b, a->freq + b->freq, createId++);
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pq.push(parent);
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}
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Node* root = pq.top();
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// <20><><EFBFBD>ɱ<EFBFBD><C9B1><EFBFBD>
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dfs(root, "");
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// <20><><EFBFBD><EFBFBD>ѹ<EFBFBD><D1B9>ǰ<EFBFBD><C7B0><EFBFBD><EFBFBD>С
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int originalBytes = text.size();
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long long bits = 0;
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for (char c : text) bits += codeMap[c].size();
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long long compressedBytes = (bits + 7) / 8;
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cout << originalBytes << " " << compressedBytes << "\n";
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// <20><><EFBFBD><EFBFBD>ĿҪ<C4BF><D2AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>루<EFBFBD><EBA3A8>Ƶ<EFBFBD><C6B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬƵ<CDAC>ʰ<EFBFBD><CAB0><EFBFBD><EFBFBD><EFBFBD>˳<EFBFBD><CBB3><EFBFBD><EFBFBD>
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vector<tuple<int,int,char>> order;
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for (auto& p : freq) {
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order.emplace_back(p.second, firstPos[p.first], p.first);
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}
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sort(order.begin(), order.end());
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for (auto& t : order) {
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char c = get<2>(t);
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cout << c << ":" << codeMap[c] << "\n";
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}
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// <20><><EFBFBD><EFBFBD>
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string out1 = decode(root, code1);
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string out2 = decode(root, code2);
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cout << out1 << "\n";
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cout << out2 << "\n";
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return 0;
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}
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