Submission #56835

#	Time	Username	Problem	Language	Result	Execution time	Memory
56835		Mamnoon_Siam	Selling RNA Strands (JOI16_selling_rna)	C++17	100 / 100	1166 ms	58724 KiB

selling_rna

//#pragma GCC optimize("Ofast,unroll-loops,no-stack-protector")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

#include <bits/stdc++.h>
using namespace std;

#define debug(s) cout<< #s <<" = "<< s <<endl
#define all(v) (v).begin(), (v).end()
#define KeepUnique(v) (v).erase( unique(all(v)), v.end() )
#define MEMSET(a,val) memset(a, val, sizeof a)
#define PB push_back
#define endl '\n'
typedef long long ll;

inline int myrand(int l, int r) {
	int ret = rand(); ret <<= 15; ret ^= rand();
	if(ret < 0) ret = -ret; ret %= (r-l+1); ret += l;
	return ret;
}
template <typename F, typename S>
ostream& operator << (ostream& os, const pair< F, S>& p) {
    return os<<"(" <<p.first<<", "<<p.second<<")"; }

typedef pair<int, int> ii;
template<typename T> using min_pq =
	priority_queue<T, vector<T>, greater<T> >;

//int dx[] = {-1, +0, +1, +0};
//int dy[] = {+0, +1, +0, -1};

int n, m;
vector<string> ok, rev;
vector<int> v;

vector<int> t[100005 * 4];

void build(int u, int b, int e, vector<int> &vec) {
	for(int i = b; i <= e; i++) t[u].push_back(vec[i]);
	sort(all(t[u]));
	if(b == e) return;
	int mid = b + e >> 1;
	build(u << 1, b, mid, vec);
	build(u << 1 | 1, mid + 1, e, vec);
}
int query(int u, int b, int e, int i, int j, int l, int r) {
	if(b > j or e < i) return 0;
	if(i <= b and e <= j) return upper_bound(all(t[u]), r) - lower_bound(all(t[u]), l);
	int mid = b + e >> 1;
	return query(u << 1, b, mid, i, j, l, r) + query(u << 1 | 1, mid + 1, e, i, j, l, r);
}
int query(int i, int j, int l, int r) {
	if(i > j or l > r) return 0;
	return query(1, 0, n - 1, i, j, l, r);
}

bool IsPrefix(string &s, string &pre) {
	if(pre.size() > s.size()) return false;
	for(int i = 0; i < pre.size(); i++) {
		if(pre[i] != s[i]) return false;
	} return true;
}

int32_t main () {
	// freopen("in", "r", stdin);
	cin >> n >> m;
	ok.resize(n), rev.resize(n);
	for(string &b : ok) cin >> b;
	sort(all(ok));
	for(int i = 0; i < n; i++) {
		rev[i] = ok[i];
		reverse(all(rev[i]));
		v.push_back(i);
	}
	sort(all(v), [](int x, int y){return rev[x] < rev[y];});
	sort(all(rev));

	build(1, 0, n - 1, v);

	// for(int i = 0; i < n; i++) cout << ok[i] << ' '; cout << endl;
	// for(int i = 0; i < n; i++) cout << rev[i] << ' '; cout << endl;
	// for(int i = 0; i < n; i++) cout << v[i] << ' '; cout << endl;

	while(m--) {
		int lo, hi;
		string pre, suf;
		cin >> pre >> suf;
		reverse(all(suf));
		int l = lower_bound(all(ok), pre) - ok.begin(), r;
		if(l >= ok.size() or !IsPrefix(ok[l], pre)) r = l - 1;
		else {
			lo = l, hi = ok.size() - 1;
			while(lo <= hi) {
				int mid = lo + hi >> 1;
				if(IsPrefix(ok[mid], pre)) {
					lo = mid + 1;
					r = mid;
				} else {
					hi = mid - 1;
				}
			}
		}
		int lit = lower_bound(all(rev), suf) - rev.begin(), rit;
		if(lit >= ok.size() or !IsPrefix(rev[lit], suf)) rit = lit - 1;
		else {
			lo = lit, hi = rev.size() - 1;
			while(lo <= hi) {
				int mid = lo + hi >> 1;
				if(IsPrefix(rev[mid], suf)) {
					lo = mid + 1;
					rit = mid;
				} else {
					hi = mid - 1;
				}
			}
		}
		// cout << "l = " << l << ", r = " << r << ", lit = " << lit << ", rit = " << rit << endl;
		cout << query(lit, rit, l, r) << endl;
	}
}

Compilation message (stderr)

selling_rna.cpp: In function 'int myrand(int, int)':
selling_rna.cpp:17:2: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  if(ret < 0) ret = -ret; ret %= (r-l+1); ret += l;
  ^~
selling_rna.cpp:17:26: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  if(ret < 0) ret = -ret; ret %= (r-l+1); ret += l;
                          ^~~
selling_rna.cpp: In function 'void build(int, int, int, std::vector<int>&)':
selling_rna.cpp:41:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid = b + e >> 1;
            ~~^~~
selling_rna.cpp: In function 'int query(int, int, int, int, int, int, int)':
selling_rna.cpp:48:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid = b + e >> 1;
            ~~^~~
selling_rna.cpp: In function 'bool IsPrefix(std::__cxx11::string&, std::__cxx11::string&)':
selling_rna.cpp:58:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < pre.size(); i++) {
                 ~~^~~~~~~~~~~~
selling_rna.cpp: In function 'int32_t main()':
selling_rna.cpp:89:8: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(l >= ok.size() or !IsPrefix(ok[l], pre)) r = l - 1;
      ~~^~~~~~~~~~~~
selling_rna.cpp:93:18: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
     int mid = lo + hi >> 1;
               ~~~^~~~
selling_rna.cpp:103:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(lit >= ok.size() or !IsPrefix(rev[lit], suf)) rit = lit - 1;
      ~~~~^~~~~~~~~~~~
selling_rna.cpp:107:18: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
     int mid = lo + hi >> 1;
               ~~~^~~~
selling_rna.cpp:53:38: warning: 'rit' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return query(1, 0, n - 1, i, j, l, r);
                                      ^
selling_rna.cpp:102:55: note: 'rit' was declared here
   int lit = lower_bound(all(rev), suf) - rev.begin(), rit;
                                                       ^~~
selling_rna.cpp:53:38: warning: 'r' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return query(1, 0, n - 1, i, j, l, r);
                                      ^
selling_rna.cpp:88:51: note: 'r' was declared here
   int l = lower_bound(all(ok), pre) - ok.begin(), r;
                                                   ^

• Subtask 1: 10 / 10
• Subtask 2: 25 / 25
• Subtask 3: 25 / 25
• Subtask 4: 40 / 40