Uva - 1598 - Exchange
本来想用优先队列做,可是不知道怎么处理之间的关系,最后还是用了map方法AC了,不过速度上有些慢,提交的时候跑了1.557秒。估计这道题时间都稍微长些,题目的时间限制也是4.5秒,不像一般题目的3秒限制。
AC代码:
#include <iostream> #include <cstdio> #include <cstdlib> #include <cctype> #include <cstring> #include <string> #include <sstream> #include <vector> #include <set> #include <map> #include <algorithm> #include <stack> #include <queue> #include <bitset> #include <cassert> using namespace std; struct CMD { string cmd; int size, price; CMD(string kind, int x = 0, int y = 0) :cmd(kind), size(x), price(y) {} }; map<int, set<int> > BUY, SELL; map<int, int> BUY_VAL, SELL_VAL; vector<CMD> D; void trade(int kind) { while (!BUY.empty() && !SELL.empty()) { if (BUY.rbegin()->first >= SELL.begin()->first) { set<int> &v1 = BUY.rbegin()->second; set<int> &v2 = SELL.begin()->second; int aid = *v1.begin(), bid = *v2.begin(); int z = min(D[aid].size, D[bid].size); printf("TRADE %d %d\n", z, kind ? D[aid].price : D[bid].price); D[aid].size -= z, D[bid].size -= z; BUY_VAL[D[aid].price] -= z, SELL_VAL[D[bid].price] -= z; if (D[aid].size == 0) v1.erase(aid); if (D[bid].size == 0) v2.erase(bid); if (v1.size() == 0) BUY.erase(D[aid].price); if (v2.size() == 0) SELL.erase(D[bid].price); } else { return; } } } // 打印QUOTE一行 void print() { while (BUY_VAL.size() && BUY_VAL.rbegin()->second == 0) { BUY_VAL.erase(BUY_VAL.rbegin()->first); } while (SELL_VAL.size() && SELL_VAL.begin()->second == 0) { SELL_VAL.erase(SELL_VAL.begin()->first); } printf("QUOTE "); if (BUY_VAL.size()) { printf("%d %d", BUY_VAL.rbegin()->second, BUY_VAL.rbegin()->first); } else { printf("0 0"); } printf(" - "); if (SELL_VAL.size()) { printf("%d %d", SELL_VAL.begin()->second, SELL_VAL.begin()->first); } else { printf("0 99999"); } cout << endl; } int main() { int Q, cases = 0; char cmd[16]; while (scanf("%d", &Q) == 1) { if (cases++) { cout << endl; } // 记得清空 BUY.clear(), SELL.clear(); BUY_VAL.clear(), SELL_VAL.clear(); D.clear(); int size, price, id; // 读入命令并处理交易 for (int i = 0; i < Q; i++) { scanf("%s", cmd); if (!strcmp(cmd, "BUY")) { scanf("%d %d", &size, &price); BUY[price].insert(i); BUY_VAL[price] += size; D.push_back(CMD("BUY", size, price)); trade(0); } else if (!strcmp(cmd, "SELL")) { scanf("%d %d", &size, &price); SELL[price].insert(i); SELL_VAL[price] += size; D.push_back(CMD("SELL", size, price)); trade(1); } else if (!strcmp(cmd, "CANCEL")) { scanf("%d", &id), id--; D.push_back(CMD("CANCEL", id)); if (D[id].cmd == "BUY") { BUY[D[id].price].erase(id); if (BUY[D[id].price].size() == 0) BUY.erase(D[id].price); BUY_VAL[D[id].price] -= D[id].size; D[id].size = 0; } if (D[id].cmd == "SELL") { SELL[D[id].price].erase(id); if (SELL[D[id].price].size() == 0) SELL.erase(D[id].price); SELL_VAL[D[id].price] -= D[id].size; D[id].size = 0; } } print(); } } return 0; }