Submission #88819

#	Time	Username	Problem	Language	Result	Execution time	Memory
88819		jasony123123	Rima (COCI17_rima)	C++11	0 / 140	22 ms	13292 KiB

rima

#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")

#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
#include <unordered_map>
//#include <ext/pb_ds/tree_policy.hpp>
//#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
//using namespace __gnu_pbds;
#define FOR(i,start,end) for(int i=start;i<(int)(end);i++)
#define FORE(i,start,end) for(int i=start;i<=(int)end;i++)
#define RFOR(i,start,end) for(int i = start; i>end; i--)
#define RFORE(i,start,end) for(int i = start; i>=end; i--)
#define all(a) a.begin(), a.end()
#define mt make_tuple
#define v vector
#define sf scanf
#define pf printf
#define dvar(x) cout << #x << " := " << x << "\n"
#define darr(x,n) FOR(i,0,n) cout << #x << "[" << i << "]" << " := " << x[i] << "\n"
typedef long long ll;
typedef long double ld;
typedef pair<int, int > pii;
typedef pair<ll, ll> pll;
//template <class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<class T> void minn(T &a, T b) { a = min(a, b); }
template<class T> void maxx(T &a, T b) { a = max(a, b); }
void io() {

	freopen("input.in", "r", stdin); freopen("output.out", "w", stdout);
	ios_base::sync_with_stdio(false); cin.tie(NULL);
}
/**************************COCI 2016-2017 R4 P5 *************************/

const int MAXL = 100000;
const int MAXN = 500000;

struct HashTool {
	const ll MOD = 1000000007LL;
	const ll PRIME = 105943LL;
	static const int SZ = MAXL;
	ll p[SZ];
	HashTool() {
		p[0] = 1;
		FOR(i, 1, SZ) p[i] = (p[i - 1] * PRIME) % MOD;
	}
	void calc(string &str, ll &full, ll &suff) {
		ll hsh = 0;
		RFORE(i, str.size() - 1, 0) {
			hsh = (hsh + ((str[i] * p[str.size() - 1 - i]) % MOD)) % MOD;
			if (i == 1) suff = hsh;
			else if (i == 0) full = hsh;
		}
	}
};

struct StringStuff {
	int len, gid;
	ll fullhsh, suffhsh;
	StringStuff(string &str, HashTool &h) {
		len = str.size();
		h.calc(str, fullhsh, suffhsh);
	}
};


int N;
HashTool ht;
v<StringStuff> vstring;

int NG = 0;
int groupsz[MAXN];
ll groupsuff[MAXN];

unordered_map<int, v<int>> allgroups;
unordered_map<int, unordered_map<ll, int>> allstring; // all hash, group id

v<int> roots;
v<int> chil[MAXN];
int ans = 0;

int dfs(int x, bool isRoot) { // 1== root, 0 = not root
	pii bst = { 0, 0 };
	for (int c : chil[x]) {
		int res = dfs(c, 0);

		if (res > bst.second)
			swap(bst.second, res);
		if (bst.second > bst.first)
			swap(bst.second, bst.first);
	}
	if (!isRoot && groupsz[x] >= 2) {
		maxx(ans, bst.first + bst.second + groupsz[x] + 1);
	}
	else
		maxx(ans, bst.first + bst.second + groupsz[x]);
	return groupsz[x] + bst.first;
}

void printGraph() {
	darr(roots, roots.size());
	FOR(i, 0, NG) {
		cout << "group: " << i << "\n";
		for (int c : chil[i])
			cout << "child: " << c << "\n";
	}
}

void buildGraph() {
	int maxlen = MAXL;
	RFORE(i, maxlen, 1) if (allgroups.find(i) != allgroups.end()) {
		for (int g : allgroups[i]) {
			if (allstring.find(i - 1) == allstring.end())
				roots.push_back(g);
			else {
				auto it = allstring[i - 1].find(groupsuff[g]);
				if (it == allstring[i - 1].end())
					roots.push_back(g);
				else
					chil[it->second].push_back(g);
			}
		}
	}
}

void printCheck() {
	dvar(N);
	FOR(i, 0, N)
		pf("string %d: len = %d    gid = %d    fullhsh = %lld    suffhsh = %lld \n", i, vstring[i].len, vstring[i].gid, vstring[i].fullhsh, vstring[i].suffhsh);
	dvar(NG);
	darr(groupsz, NG);
	darr(groupsuff, NG);

	int maxlen = MAXL;
	RFORE(i, maxlen, 1) {
		if (allgroups.find(i) != allgroups.end()) {
			cout << "at length " << i << "\n";
			for (int g : allgroups[i])
				cout << "group " << g << "\n";
		}
		if (allstring.find(i) != allstring.end()) {
			cout << "at length " << i << "\n";
			for (auto g : allstring[i])
				cout << "allhash " << g.first << " groupid " << g.second << "\n";
		}
	}
}

void genGroups() {
	map<pair<int, ll>, v<int> > same;
	FOR(i, 0, N)
		same[{vstring[i].len, vstring[i].suffhsh}].push_back(i);
	for (auto &group : same) {
		groupsz[NG] = group.second.size();
		groupsuff[NG] = group.first.second;
		allgroups[group.first.first].push_back(NG);
		for (auto &str : group.second) {
			vstring[str].gid = NG;
			allstring[group.first.first][vstring[str].fullhsh] = NG;
		}
		NG++;
	}
}

int main() {
	io();
	cin >> N;
	FOR(i, 0, N) {
		string str;
		cin >> str;
		vstring.push_back(StringStuff(str, ht));
	}

	genGroups();
//	printCheck();

	buildGraph();
//	printGraph();

	for (int r : roots)
		dfs(r, 1);
	cout << ans << "\n";
	return 0;
}

Compilation message (stderr)

rima.cpp: In function 'void io()':
rima.cpp:31:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  freopen("input.in", "r", stdin); freopen("output.out", "w", stdout);
  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
rima.cpp:31:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  freopen("input.in", "r", stdin); freopen("output.out", "w", stdout);
                                   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 140