Submission #1117497

#	Time	Username	Problem	Language	Result	Execution time	Memory
1117497		KALARRY	Global Warming (CEOI18_glo)	C++14	100 / 100	60 ms	7056 KiB

glo

//chockolateman

#include<bits/stdc++.h>

using namespace std;

const long long INF = 1e15;

long long N,x,t[200005],suff[200005],dp[200005]; //suff[i] = LIC of the suff i starting with at least t[i-1] - d + 1

int main()
{
    scanf("%lld%lld",&N,&x);
    for(long long i = 1 ; i <= N ; i++)
        scanf("%lld",&t[i]);
    dp[0] = INF;
    for(long long i = 1 ; i <= N ; i++)
        dp[i] = - INF;
    for(long long i = N ; i >= 1 ; i--)
    {
        long long pos = 0;
        for(long long b = N ; b >= 1 ; b/=2)
            while(pos + b <= N && dp[pos+b] > t[i])
                pos += b;
        dp[pos+1] = max(dp[pos+1],t[i]);
        pos = 0;
        for(long long b = N ; b >= 1 ; b/=2)
            while(pos + b <= N && dp[pos+b] > t[i-1] - x)
                pos += b;
        suff[i] = pos;
    }
    long long ans = 0;
    for(long long i = 1 ; i <= N ; i++)
        dp[i] = INF;
    dp[0] = 0;
    for(long long i = 1 ; i <= N ; i++)
    {
        long long pos = lower_bound(dp,dp+N+1,t[i]) - dp - 1;
        dp[pos+1] = min(dp[pos+1],t[i]);
        ans = max(ans,pos+1 + suff[i+1]);
    }
    printf("%lld\n",ans);
    return 0;
}

Compilation message (stderr)

glo.cpp: In function 'int main()':
glo.cpp:13:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |     scanf("%lld%lld",&N,&x);
      |     ~~~~~^~~~~~~~~~~~~~~~~~
glo.cpp:15:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |         scanf("%lld",&t[i]);
      |         ~~~~~^~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 13 / 13
• Subtask 4: 10 / 10
• Subtask 5: 20 / 20
• Subtask 6: 17 / 17
• Subtask 7: 25 / 25