Submission #199929

#	Time	Username	Problem	Language	Result	Execution time	Memory
199929		SamAnd	Rabbit Carrot (LMIO19_triusis)	C++17	100 / 100	375 ms	25828 KiB

triusis

#include <bits/stdc++.h>
using namespace std;
const int N = 500005;

int n, m;
int a[N];

int z;
vector<long long> v;
map<long long, int> mp;

int t[N * 4];
void ubd(int tl, int tr, int x, int y, int pos)
{
    if (tl == tr)
    {
        t[pos] = min(t[pos], y);
        return;
    }
    int m = (tl + tr) / 2;
    if (x <= m)
        ubd(tl, m, x, y, pos * 2);
    else
        ubd(m + 1, tr, x, y, pos * 2 + 1);
    t[pos] = min(t[pos * 2], t[pos * 2 + 1]);
}
int qry(int tl, int tr, int l, int r, int pos)
{
    if (l > r)
        return N;
    if (tl == l && tr == r)
        return t[pos];
    int m = (tl + tr) / 2;
    return min(qry(tl, m, l, min(m, r), pos * 2),
               qry(m + 1, tr, max(m + 1, l), r, pos * 2 + 1));
}

int dp[N];
int main()
{
    scanf("%d%d", &n, &m);
    for (int i = 1; i <= n; ++i)
        scanf("%d", &a[i]);
    for (int i = 0; i <= n; ++i)
    {
        v.push_back(a[i] - i * 1LL * m);
    }
    sort(v.begin(), v.end());
    for (int i = 0; i < v.size(); ++i)
    {
        if (!i || v[i] != v[i - 1])
            mp[v[i]] = ++z;
    }
    for (int i = 0; i <= n; ++i)
    {
        a[i] = mp[a[i] - i * 1LL * m];
    }
    for (int i = 0; i < N * 4; ++i)
        t[i] = N;
    ubd(1, z, a[0], dp[0], 1);
    for (int i = 1; i <= n; ++i)
    {
        dp[i] = qry(1, z, a[i], z, 1) + i - 1;
        ubd(1, z, a[i], dp[i] - i, 1);
    }
    int ans = n;
    for (int i = 1; i <= n; ++i)
        ans = min(ans, dp[i] + (n - i));
    printf("%d\n", ans);
    return 0;
}

Compilation message (stderr)

triusis.cpp: In function 'int main()':
triusis.cpp:49:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < v.size(); ++i)
                     ~~^~~~~~~~~~
triusis.cpp:41:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &n, &m);
     ~~~~~^~~~~~~~~~~~~~~~
triusis.cpp:43:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &a[i]);
         ~~~~~^~~~~~~~~~~~~

• Subtask 1: 14 / 14
• Subtask 2: 21 / 21
• Subtask 3: 28 / 28
• Subtask 4: 37 / 37