Submission #64309

#	Time	Username	Problem	Language	Result	Execution time	Memory
64309		antimirage	parentrises (BOI18_parentrises)	C++17	100 / 100	273 ms	110116 KiB

parentrises

#include <iostream>
#include <assert.h>
#include <stdio.h>
#include <iomanip>
#include <utility>
#include <random>
#include <math.h>
#include <time.h>
#include <vector>
#include <set>
#include <map>
#include <algorithm>
#include <string.h>

#define fr first
#define sc second
#define mk make_pair
#define pb push_back
#define sz(s) (int)s.size()
#define all(s) s.begin(), s.end()

using namespace std;

const int N = 305, mod = 1e9 + 7, M = 1e6 + 5;

int type, tests, dp[N][N + N][N], x, res;

int pref[2][M], n, mn[2], bal1, bal2, sum[2][M], bal;

char s[M], ans[M];

bool fl;

main()
{
    cin >> type >> tests;

    if (type == 2)
    {
        dp[0][0][0] = 1;

        for (int i = 1; i <= 300; i++)
            for (int j = 0; j <= i + i; j++)
                for (int k = 0; k <= i; k++)
                {
                    if (j >= 2 && k >= 1)
                    {
                        dp[i][j][k] += dp[i - 1][j - 2][k - 1];
                        dp[i][j][k] %= mod;
                    }
                    if (j < i + i)
                    {
                        if (k == 0)
                        {
                            dp[i][j][k] += dp[i - 1][j + 1][k];
                            dp[i][j][k] %= mod;
                            dp[i][j][k] += dp[i - 1][j + 1][k + 1];
                            dp[i][j][k] %= mod;
                            dp[i][j][k] += dp[i - 1][j + 1][k + 2];
                            dp[i][j][k] %= mod;
                        }
                        else
                        {
                            dp[i][j][k] += dp[i - 1][j + 1][k + 2];
                            dp[i][j][k] %= mod;
                        }
                    }
                }
        while (tests--)
        {
            res = 0;
            scanf("%d", &x);
            for (int i = 0; i <= x; i++)
                res += dp[x][i][0], res %= mod;

            printf("%d\n", res);
        }
    }
    else
    {
        while (tests--)
        {
            fl = false;
            bal = 0;
            scanf("%s", s + 1);

            n = strlen(s + 1);

            if (s[n] == '(')
                    fl = 1;

            for (int i = 1; i <= n; i++)
            {
                pref[0][i] = pref[1][i] = 0;
                sum[0][i] = sum[1][i] = 0;
                if ( s[i] == '(' )
                    pref[0][i] = 1, pref[1][i] = 1, ans[i] = 'G', bal += 2;
                else
                {
                    if (pref[0][i - 1] > pref[1][i - 1])
                        ans[i] = 'R', pref[0][i] = -1;
                    else
                        ans[i] = 'B', pref[1][i] = -1;

                    bal--;
                }
                pref[0][i] += pref[0][i - 1];
                pref[1][i] += pref[1][i - 1];

                if (bal < 0)
                    fl = 1;
            }
            bal1 = pref[0][n];
            bal2 = pref[1][n];
            mn[0] = mn[1] = 1e9 + 7;

            for (int i = n; i >= 1; i--)
            {
                mn[0] = min( mn[0], pref[0][i] );
                mn[1] = min( mn[1], pref[1][i] );
                if ( ans[i] == 'R' && mn[1] > 0 )
                {
                    sum[1][i] = -1;
                    ans[i] = 'G';
                    mn[1]--;
                    bal2--;
                }
                if ( ans[i] == 'B' && mn[0] > 0)
                {
                    sum[0][i] = -1;
                    ans[i] = 'G';
                    mn[0]--;
                    bal1--;
                }
            }
            for (int i = 1; i <= n; i++)
            {
                sum[0][i] += sum[0][i - 1];
                sum[1][i] += sum[1][i - 1];
                pref[0][i] += sum[0][i];
                pref[1][i] += sum[1][i];
            }
            mn[0] = mn[1] = 1e9 + 7;

            for (int i = n; i >= 1; i--)
            {
                mn[0] = min( mn[0], pref[0][i] );
                mn[1] = min( mn[1], pref[1][i] );
                if (s[i] == ')') continue;
                if (mn[0] > 0 && bal1 > bal2)
                {
                    ans[i] = 'B';
                    mn[0]--;
                    bal1--;
                }
                else if (mn[1] > 0)
                {
                    ans[i] = 'R';
                    mn[1]--;
                    bal2--;
                }
            }
            if (bal < 0 || bal > n) fl = 1;

            reverse(s + 1, s + n + 1);

            bal = 0;

            for (int i = 1; i <= n; i++)
            {
                if ( s[i] == '(' )
                    bal--;
                else
                    bal += 2;

                if (bal < 0)
                    fl = 1;
            }
            if (bal < 0 || bal > n) fl = 1;

            if (fl)
                puts("impossible");
            else
            {
                for (int i = 1; i <= n; i++)
                    printf("%c", ans[i]);
                printf("\n");
            }
        }
    }
}

Compilation message (stderr)

parentrises.cpp:34:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main()
      ^
parentrises.cpp: In function 'int main()':
parentrises.cpp:72:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d", &x);
             ~~~~~^~~~~~~~~~
parentrises.cpp:85:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%s", s + 1);
             ~~~~~^~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 11 / 11
• Subtask 3: 6 / 6
• Subtask 4: 28 / 28
• Subtask 5: 6 / 6
• Subtask 6: 16 / 16
• Subtask 7: 28 / 28