Submission #900157

#	Time	Username	Problem	Language	Result	Execution time	Memory
900157		andrei_iorgulescu	JJOOII 2 (JOI20_ho_t2)	C++14	100 / 100	10 ms	5984 KiB

ho_t2

#include <bits/stdc++.h>

using namespace std;

int inf = 1e9;

int n,k;
char sir[200005];
int a[200005];
int next0[200005],next1[200005],next2[200005];
vector<int>pos0,pos1,pos2;
int p[200005];

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    cin >> n >> k;
    for (int i = 1; i <= n; i++)
        cin >> sir[i];
    for (int i = 1; i <= n; i++)
    {
        if (sir[i] == 'J')
            a[i] = 0;
        else if (sir[i] == 'O')
            a[i] = 1;
        else
            a[i] = 2;
    }
    next0[n] = next1[n] = next2[n] = n + 1;
    for (int i = n - 1; i >= 1; i--)
    {
        next0[i] = next0[i + 1];
        next1[i] = next1[i + 1];
        next2[i] = next2[i + 1];
        if (a[i + 1] == 0)
            next0[i] = i + 1;
        if (a[i + 1] == 1)
            next1[i] = i + 1;
        if (a[i + 1] == 2)
            next2[i] = i + 1;
    }
    next0[n + 1] = next1[n + 1] = next2[n + 1] = n + 1;
    for (int i = 1; i <= n; i++)
    {
        if (a[i] == 0)
            pos0.push_back(i),p[i] = pos0.size() - 1;
        if (a[i] == 1)
            pos1.push_back(i),p[i] = pos1.size() - 1;
        if (a[i] == 2)
            pos2.push_back(i),p[i] = pos2.size() - 1;
    }
    int ans = 1e9;
    p[n + 1] = n + 1;
    for (int i = 1; i <= n; i++)
    {
        if (a[i] == 0)
        {
            if (p[i] + k - 1 < pos0.size())
            {
                int x = pos0[p[i] + k - 1];
                int x0 = next1[x];
                if (p[x0] + k - 1 < pos1.size())
                {
                    int x1 = pos1[p[x0] + k - 1];
                    int x2 = next2[x1];
                    if (p[x2] + k - 1 < pos2.size())
                    {
                        int x3 = pos2[p[x2] + k - 1];
                        ans = min(ans,x3 - i + 1 - 3 * k);
                    }
                }
            }
        }
    }
    if (ans == inf)
        cout << -1;
    else
        cout << ans;
    return 0;
}

Compilation message (stderr)

ho_t2.cpp: In function 'int main()':
ho_t2.cpp:60:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   60 |             if (p[i] + k - 1 < pos0.size())
      |                 ~~~~~~~~~~~~~^~~~~~~~~~~~~
ho_t2.cpp:64:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   64 |                 if (p[x0] + k - 1 < pos1.size())
      |                     ~~~~~~~~~~~~~~^~~~~~~~~~~~~
ho_t2.cpp:68:39: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   68 |                     if (p[x2] + k - 1 < pos2.size())
      |                         ~~~~~~~~~~~~~~^~~~~~~~~~~~~

• Subtask 1: 1 / 1
• Subtask 2: 12 / 12
• Subtask 3: 87 / 87