Submission #850879

#	Time	Username	Problem	Language	Result	Execution time	Memory
850879		danikoynov	Chorus (JOI23_chorus)	C++14	40 / 100	30 ms	2648 KiB

chorus

/**
 ____ ____ ____ ____ ____ ____
||l |||e |||i |||n |||a |||d ||
||__|||__|||__|||__|||__|||__||
|/__\|/__\|/__\|/__\|/__\|/__\|

**/

#include<bits/stdc++.h>
#define endl '\n'

using namespace std;
typedef long long ll;

void speed()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
}

const int maxn = 510;
int n, k;
string s;

int dp[maxn][maxn], pos[2][maxn];
/**

*/

void chmin(int &var, int val) /// careful for long long
{
    var = min(var, val);
}

void solve()
{
    cin >> n >> k >> s;

    s = "#" + s;
    int cntA = 0, cntB = 0;
    for (int i = 1; i <= 2 * n; i ++)
    {
        if (s[i] == 'A')
        {
            cntA ++;
            pos[0][cntA] = i;
        }
        else
        {
            cntB ++;
            pos[1][cntB] = i;
        }
    }

    for (int i = 0; i <= n; i ++)
        for (int j = 0; j <= n; j ++)
        dp[i][j] = 4 * n * n; /// careful for overflow

        int cr = 0;
    for (int j = 1; j <= n; j ++)
    {
        cr = cr + pos[0][j] - j;

        dp[1][j] = cr;
    }

    for (int i = 1; i < k; i ++)
    {
        for (int j = 1; j <= n; j ++)
        {
            if (dp[i][j] == 4 * n * n)
                continue;
            /// i-th song, j open brackets, k - in the last one
            /// range [j * 2 - k + 1, j * 2]
            ///if (dp[i][j][k] == 0)
            ///cout << "state " << i << " " << j << " " << k << " = " << dp[i][j][k] << endl;
            int tk = 0, atl = j * 2 - k + 1, atm = j * 2 + 1;
            for (int fix = 1; fix <= n - j; fix ++)
            {
                ///if (pos[0][fix + j] < atl)
                   // tk += atl - pos[0][fix + j];
                ///else
                if (pos[0][fix + j] > atm)
                    tk += pos[0][fix + j] - atm;
            //cout << "transition " << fix << " " << tk << endl;
                ///cout << dp[i][j][k] + tk << " " << tk << endl;
                chmin(dp[i + 1][j + fix], dp[i][j] + tk);
                atl ++;
                atm ++;
            }



        }
    }

    int ans = 4 * n * n;
    for (int i = 1; i <= k; i ++)
        ans = min(ans, dp[i][n]);
    cout << ans << endl;
}

int main()
{
    ///freopen("test.txt", "r", stdin);
    solve();
    return 0;
}

Compilation message (stderr)

chorus.cpp: In function 'void solve()':
chorus.cpp:56:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   56 |     for (int i = 0; i <= n; i ++)
      |     ^~~
chorus.cpp:60:9: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   60 |         int cr = 0;
      |         ^~~

• Subtask 1: 16 / 16
• Subtask 2: 24 / 24
• Subtask 3: 0 / 21
• Subtask 4: 0 / 26
• Subtask 5: 0 / 13