Submission #197369

#	Time	Username	Problem	Language	Result	Execution time	Memory
197369		Pankin	Hidden Sequence (info1cup18_hidden)	C++14	100 / 100	10 ms	428 KiB

hidden

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include "grader.h"
 
/*
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("-O3")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
*/
 
#define mp make_pair
#define ll long long
#define ld long double
#define pb push_back
#define fast_io ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define fs first
#define sc second
#define getfiles ifstream cin("input.txt"); ofstream cout("output.txt");
#define endl '\n'
#define pii pair<int, int>
 
const int INF = 2000000005;
const ll BIG_INF = 2000000000000000005;
const int mod = 1000000007;
const int P = 31;
const ld PI = 3.141592653589793238462643;
const double eps = 1e-9;
 
using namespace std;
using namespace __gnu_pbds;
 
bool valid(int x, int y, int n, int m) {
    return x >= 0 && y >= 0 && x < n && y < m;
}
 
mt19937 rng(1999999973);
 
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
 
static int maxQ = 0;
static vector < int > theRealAnswer;
 
map<int, bool> fin;
 
inline pii getBlock(int num, vector<int> &ans) {
    int cur = 0, l;
    for (int i = 0; ; i++) {
        if (i == ans.size())
            return mp(-1, -1);
        if (i != 0 && ans[i] != ans[i - 1])
            cur++;
        if (cur == num) {
            l = i;
            break;
        }
    }
    int r = l;
    while(r + 1 < ans.size() && ans[r + 1] == ans[l])
        r++;
    return mp(l, r);
}
 
inline void doBlock(int i, vector<int> &ans, int &ad, int &n, int l, int r) {
 
    int cursize = getBlock(i, ans).sc - getBlock(i, ans).fs + 1;
    vector<int> cur;
 
    int curBlock = 0;
    cur.pb(ans[0]);
    if (i != 0) {
        cur.pop_back();
        curBlock++;
        cur.pb(ans[getBlock(1, ans).fs]);
    }
 
    while(curBlock != i) {
        pii otr = getBlock(curBlock, ans);
        if (curBlock + 2 <= i && otr.fs == otr.sc) {
            cur.pb(ans[otr.fs]);
            curBlock += 2;
            continue;
        }
        else {
            cur.pb(ans[otr.sc + 1]);
            curBlock++;
            continue;
        }
    }
 
    int val = ans[getBlock(curBlock, ans).fs];
    for (int i = 0; i < cursize; i++)
        cur.pb(val);
 
 
    curBlock += 2;
 
    while(getBlock(curBlock, ans) != mp(-1, -1)) {
        pii otr = getBlock(curBlock, ans);
        if (otr.fs == otr.sc && ans[otr.fs] == (val ^ 1)) {
            cur.pb(ans[otr.fs]);
            curBlock += 2;
            continue;
        }
        else {
            cur.pb(ans[otr.sc] ^ 1);
            curBlock++;
            continue;
        }
    }
 
    if (cur.size() > n / 2 + 1) {
        return;
    }
 
//    for (int i = 0; i < cur.size(); i++)
//        cout << cur[i] << " ";
//    cout << endl;
    if (!isSubsequence(cur)) {
        fin[i] = true;
        return;
    }
    ans.insert(ans.begin() + l, ans[r]);
    ad++;
    doBlock(i, ans, ad, n, l, r + 1);
}
 
vector<int> findSequence(int n) {
    int sw = 0, col = -1;
    for (int i = 0; i <= n / 2 + 1; i++) {
        vector<int> seq;
        for (int j = 0; j < i; j++)
            seq.pb(0);
        if (!isSubsequence(seq)) {
            col = i - 1;
            break;
        }
    }
 
    if (col == -1) {
        sw = 1;
        for (int i = 0; i <= n / 2 + 1; i++) {
            vector<int> seq;
            for (int j = 0; j < i; j++)
                seq.pb(1);
            if (!isSubsequence(seq)) {
                col = i - 1;
                break;
            }
        }
    }
 
    vector<int> ans, cur;
    if (col == 0) {
        for (int i = 0; i < n; i++) {
            ans.pb(sw ^ 1);
        }
        return ans;
    }
 
    for (int i = 0; i < col; i++)
        ans.pb(sw);
    cur = ans;
    int ad = 0;
    for (int i = 0; i <= col; i++) {
        cur.insert(cur.begin() + i, 1 ^ sw);
        if (isSubsequence(cur)) {
            ans.insert(ans.begin() + i + ad, 1 ^ sw);
            ad++;
        }
        cur.erase(cur.begin() + i);
    }
 
    cur.clear();
    for (int i = 0; getBlock(i, ans) != mp(-1, -1); i++) {
        pii co = getBlock(i, ans);
        int l = co.fs, r = co.sc;
        if (ans[l] == sw)
            continue;
        doBlock(i, ans, ad, n, l, r);
    }
 
    for (int i = 0; getBlock(i, ans) != mp(-1, -1); i++) {
        pii co = getBlock(i, ans);
        int l = co.fs, r = co.sc;
        if (ans[l] == sw)
            continue;
        if (fin[i])
            continue;
        for (int j = 0; j < n - col - ad; j++)
            ans.insert(ans.begin() + l, sw ^ 1);
        break;
    }
 
    return ans;
}

Compilation message (stderr)

hidden.cpp: In function 'std::pair<int, int> getBlock(int, std::vector<int>&)':
hidden.cpp:50:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if (i == ans.size())
             ~~^~~~~~~~~~~~~
hidden.cpp:60:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     while(r + 1 < ans.size() && ans[r + 1] == ans[l])
           ~~~~~~^~~~~~~~~~~~
hidden.cpp: In function 'void doBlock(int, std::vector<int>&, int&, int&, int, int)':
hidden.cpp:113:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if (cur.size() > n / 2 + 1) {
         ~~~~~~~~~~~^~~~~~~~~~~
hidden.cpp: In function 'std::vector<int> findSequence(int)':
hidden.cpp:186:24: warning: unused variable 'r' [-Wunused-variable]
         int l = co.fs, r = co.sc;
                        ^
hidden.cpp: At global scope:
hidden.cpp:42:12: warning: 'maxQ' defined but not used [-Wunused-variable]
 static int maxQ = 0;
            ^~~~
grader.cpp: In function 'int main()':
grader.cpp:28:43: warning: format '%d' expects argument of type 'int', but argument 3 has type 'std::vector<int>::size_type {aka long unsigned int}' [-Wformat=]
     fprintf (fifo_out, "%d\n", ans.size ());
                                ~~~~~~~~~~~^
grader.cpp:29:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i=0; i<ans.size () && i < N; i++)
                   ~^~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 80 / 80