E - Kth Takoyaki Set
E - Kth Takoyaki Set
https://atcoder.jp/contests/abc297/tasks/abc297_e
思路
使用优先队列,从0 开始, 对所有可能的扩展,计算累加和, 添加到队列,
每次从队列取出最小值,直到取出第k个。
Code
#include <iomanip> #include <bits/stdc++.h> #include <iostream> using namespace std; #include <limits.h> #include <math.h> #include <vector> #include <set> #include <map> #include <stack> #include <queue> typedef long long LL; typedef pair<int, int> pii; typedef pair<LL, LL> pll; typedef pair<string, string> pss; typedef vector<int> vi; typedef vector<vi> vvi; typedef vector<pii> vii; typedef vector<LL> vl; typedef vector<vl> vvl; double EPS = 1e-9; int INF = 1000000005; long long INFF = 1000000000000000005LL; double PI = acos(-1); int dirx[8] = { -1, 0, 0, 1, -1, -1, 1, 1 }; int diry[8] = { 0, 1, -1, 0, -1, 1, -1, 1 }; #ifdef TESTING #define DEBUG fprintf(stderr, "====TESTING====\n") #define VALUE(x) cerr << "The value of " << #x << " is " << x << endl #define debug(...) fprintf(stderr, __VA_ARGS__) #else #define DEBUG #define VALUE(x) #define debug(...) #endif #define FOR(a, b, c) for (int(a) = (b); (a) < (c); ++(a)) #define FORN(a, b, c) for (int(a) = (b); (a) <= (c); ++(a)) #define FORD(a, b, c) for (int(a) = (b); (a) >= (c); --(a)) #define FORSQ(a, b, c) for (int(a) = (b); (a) * (a) <= (c); ++(a)) #define FORC(a, b, c) for (char(a) = (b); (a) <= (c); ++(a)) #define FOREACH(a, b) for (auto&(a) : (b)) #define REP(i, n) FOR(i, 0, n) #define REPN(i, n) FORN(i, 1, n) #define MAX(a, b) a = max(a, b) #define MIN(a, b) a = min(a, b) #define SQR(x) ((LL)(x) * (x)) #define RESET(a, b) memset(a, b, sizeof(a)) #define fi first #define se second #define mp make_pair #define pb push_back #define ALL(v) v.begin(), v.end() #define ALLA(arr, sz) arr, arr + sz #define SIZE(v) (int)v.size() #define SORT(v) sort(ALL(v)) #define REVERSE(v) reverse(ALL(v)) #define SORTA(arr, sz) sort(ALLA(arr, sz)) #define REVERSEA(arr, sz) reverse(ALLA(arr, sz)) #define PERMUTE next_permutation #define TC(t) while (t--) /******************************** COMMON FUNC START ***************************************/ inline string IntToString(LL a) { char x[100]; sprintf(x, "%lld", a); string s = x; return s; } inline LL StringToInt(string a) { char x[100]; LL res; strcpy(x, a.c_str()); sscanf(x, "%lld", &res); return res; } inline string GetString(void) { char x[1000005]; scanf("%s", x); string s = x; return s; } inline string uppercase(string s) { int n = SIZE(s); REP(i, n) if (s[i] >= 'a' && s[i] <= 'z') s[i] = s[i] - 'a' + 'A'; return s; } inline string lowercase(string s) { int n = SIZE(s); REP(i, n) if (s[i] >= 'A' && s[i] <= 'Z') s[i] = s[i] - 'A' + 'a'; return s; } inline void OPEN(string s) { #ifndef TESTING freopen((s + ".in").c_str(), "r", stdin); freopen((s + ".out").c_str(), "w", stdout); #endif } /******************************** COMMON FUNC END ***************************************/ /******************************** GRAPH START ***************************************/ // Graph class represents a directed graph // using adjacency list representation class Graph { public: map<int, bool> visited; map<int, list<int> > adj; // function to add an edge to graph void addEdge(int v, int w); // DFS traversal of the vertices // reachable from v void DFS(int v); }; void Graph::addEdge(int v, int w) { adj[v].push_back(w); // Add w to v’s list. } void Graph::DFS(int v) { // Mark the current node as visited and // print it visited[v] = true; cout << v << " "; // Recur for all the vertices adjacent // to this vertex list<int>::iterator i; for (i = adj[v].begin(); i != adj[v].end(); ++i) if (!visited[*i]) DFS(*i); } /******************************** GRAPH END ***************************************/ /* https://atcoder.jp/contests/abcxxx/tasks/abcxxx_d */ LL n, k; vector<LL> a; map<LL, bool> visited; priority_queue<LL, vector<LL>, greater<LL> > pq; int main() { cin >> n >> k; for(int i=0; i<n; i++){ LL temp; cin >> temp; a.push_back(temp); } sort(a.begin(), a.end()); pq.push(0); visited[0] = true; LL order = -1; while(!pq.empty()){ LL first = pq.top(); pq.pop(); // cout << "first = " << first << endl; order++; // cout << "order = " << order << endl; if (order == k){ // cout << "found!" << endl; cout << first << endl; break; } for(int i=0; i<a.size(); i++){ LL gain = a[i]; LL next = first + gain; if (visited[next]){ continue; } // cout << "next ="<< next << endl; visited[next] = true; pq.push(next); } } return 0; }
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