Submission #98810

#	Time	Username	Problem	Language	Result	Execution time	Memory
98810		bogdan10bos	Growing Vegetable is Fun 3 (JOI19_ho_t3)	C++14	100 / 100	273 ms	325632 KiB

joi2019_ho_t3

#include <bits/stdc++.h>

using namespace std;

//#define FILE_IO

typedef pair<int, int> pii;
typedef pair<int, pii> p3i;

int N;
string s;

int getid(char ch)
{
    if(ch == 'R')   return 0;
    if(ch == 'G')   return 1;
    if(ch == 'Y')   return 2;
    return -1;
}
char idtochar(int id)
{
    if(id == 0) return 'R';
    if(id == 1) return 'G';
    if(id == 2) return 'Y';
    return 0;
}

int dp[405][405][405][3];  /// dp[r][g][y]
int lst[405][405][405][3];
vector<p3i> pos[3];

int cost(p3i x, p3i y)
{
    int ans = 0;
    ans += abs(x.first - y.first);
    ans += abs(x.second.first - y.second.first);
    ans += abs(x.second.second - y.second.second);
    return ans;
}

int main()
{
    #ifdef FILE_IO
    freopen("1.in", "r", stdin);
    freopen("1.out", "w", stdout);
    #endif

    cin >> N;
    cin >> s;

    int f[3];
    f[0] = f[1] = f[2] = 0;
    for(int i = 0; i < N; i++)
    {
        f[getid(s[i])]++;
        pos[getid(s[i])].push_back({ f[0], {f[1], f[2]} });
    }

    int R = pos[0].size(), G = pos[1].size(), Y = pos[2].size();

    int mx = max({R, G, Y});
    if(mx > (N + 1) / 2)
    {
        printf("-1\n");
        exit(0);
    }

    for(int r = 0; r <= R; r++)
        for(int g = 0; g <= G; g++)
            for(int y = 0; y <= Y; y++)
            {
                int p = r + g + y;
                if(p == 0)  continue;

                dp[r][g][y][0] = dp[r][g][y][1] = dp[r][g][y][2] = 1 << 30;
                if(r > 0)
                {
                    dp[r][g][y][0] = min(dp[r - 1][g][y][1], dp[r - 1][g][y][2]) + cost(pos[0][r - 1], {r, {g, y}});
                    lst[r][g][y][0] = (dp[r - 1][g][y][1] > dp[r - 1][g][y][2]) ? 2 : 1;
                }
                if(g > 0)
                {
                    dp[r][g][y][1] = min(dp[r][g - 1][y][0], dp[r][g - 1][y][2]) + cost(pos[1][g - 1], {r, {g, y}});
                    lst[r][g][y][1] = (dp[r][g - 1][y][0] > dp[r][g - 1][y][2]) ? 2 : 0;
                }
                if(y > 0)
                {
                    dp[r][g][y][2] = min(dp[r][g][y - 1][0], dp[r][g][y - 1][1]) + cost(pos[2][y - 1], {r, {g, y}});
                    lst[r][g][y][2] = (dp[r][g][y - 1][0] > dp[r][g][y - 1][1]) ? 1 : 0;
                }
            }

    int ans = min({ dp[R][G][Y][0], dp[R][G][Y][1], dp[R][G][Y][2] });
    ans /= 2;
    cout << ans << '\n';

    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 55 / 55
• Subtask 3: 15 / 15
• Subtask 4: 25 / 25