Submission #432021

#	Time	Username	Problem	Language	Result	Execution time	Memory
432021		ak2006	Untitled (POI11_tem)	C++14	0 / 100	52 ms	65540 KiB

Main

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vb = vector<bool>;
using vvb = vector<vb>;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vc = vector<char>;
using vvc = vector<vc>;
using vs = vector<string>;
const ll mod = 1e9 + 7,inf = 1e18;
#define pb push_back
#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define lc 2 * no
#define rc 2 * no + 1
void setIO()
{
    fast;
    #ifndef ONLINE_JUDGE
    freopen("input.txt","r",stdin);
    freopen("output.txt","w",stdout);
    #endif
}
int n = 1e6 + 5;
vi a(n),b(n),l2(n);
vvi dp(n,vi(21));
void build()
{
    l2[1] = 0,dp[1][0] = a[1];
    for (int i = 2;i<=n;i++)l2[i] = l2[i/2] + 1,dp[i][0] = a[i];
    for (int i = n;i>=1;i--)
        for (int j = 1;(1<<j) + i <= n;j++)
            dp[i][j] = max(dp[i][j - 1],dp[i + (1<<(j - 1))][j - 1]);
}
int MAX(int l,int r)
{
    int len = l2[r - l + 1];
    return max(dp[l][len],dp[r - (1<<len) + 1][len]);
}
int search(int i)
{
    //binary search for the smallest j such that MAX(1,1,n,j,i) <= b[i]
    int l = 1,r = i,pos = i;
    while (l <= r){
        int mid = (l + r)/2;
        if (MAX(mid,i) <= b[i]){
            pos = mid;
            r = mid - 1;
        }
        else l = mid + 1;
    }
    return pos;
}
int main()
{
    setIO();
    cin>>n;
    for (int i = 1;i<=n;i++)cin>>a[i]>>b[i];
    build();
    int cur = search(1);
    int ans = 1 - cur + 1;
    for (int i = 2;i<=n;i++){
        int val = search(i);
        int now = max(val,cur);
        ans = max(ans,i - now + 1);
        cur = max(cur,val);
    }
    cout<<ans;
    return 0;
}

Compilation message (stderr)

tem.cpp: In function 'void setIO()':
tem.cpp:22:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   22 |     freopen("input.txt","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
tem.cpp:23:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   23 |     freopen("output.txt","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 8
• Subtask 2: 0 / 8
• Subtask 3: 0 / 8
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• Subtask 11: 0 / 9
• Subtask 12: 0 / 9