Submission #835982

#	Time	Username	Problem	Language	Result	Execution time	Memory
835982		kwongweng	Feast (NOI19_feast)	C++17	100 / 100	125 ms	10564 KiB

feast

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef long double ld;
typedef pair<ll, ll> pll;
#define FOR(i, a, b) for(int i = a; i < b; i++)
#define ROF(i, a, b) for(int i = a; i >= b; i--)
#define ms memset
#define pb push_back
#define fi first
#define se second
 
const ll INF = 1e18;
 
void solve(){
  int n, k; cin>>n>>k;
  vi a(n+1); FOR(i,1,n+1) cin>>a[i];
  vector<ll> s(n+1); FOR(i,1,n+1) s[i]=s[i-1]+a[i];
  vector<ll> dp(n+1);
  ll l=0,r=1e15; 
  while (r-l>1){
    ll m=(l+r)/2;
    vi seg(n+1); FOR(i,1,n+1) dp[i]=INF;
    ll mx=0;
    int cur=0;
    FOR(i,1,n+1){
      dp[i]=s[i]+mx-m;
      seg[i]=cur+1;
      if (dp[i-1]>dp[i]){
        dp[i]=dp[i-1];
        seg[i]=seg[i-1];
      }
      if (dp[i]-s[i]==mx) cur=max(cur,seg[i]);
      if (dp[i]-s[i]>mx){
        mx=dp[i]-s[i]; cur=seg[i];
      }
    }
    if (seg[n]<k) r=m;
    else l=m;
  }
  vi seg(n+1); FOR(i,1,n+1) dp[i]=INF;
    ll mx=0;
    int cur=0;
    FOR(i,1,n+1){
      dp[i]=s[i]+mx-l;
      seg[i]=cur+1;
      if (dp[i-1]>dp[i]){
        dp[i]=dp[i-1];
        seg[i]=seg[i-1];
      }
      if (dp[i]-s[i]==mx) cur=max(cur,seg[i]);
      if (dp[i]-s[i]>mx){
        mx=dp[i]-s[i]; cur=seg[i];
      }
    }
  cout<<dp[n]+(ll)k*(ll)l;
}
 
int main(){
	//MOD=MOD1;
    ios::sync_with_stdio(false);
    if (fopen("input.txt", "r")) {
		  freopen("input.txt", "r", stdin);
    	freopen("output.txt", "w", stdout);
	  }
    int TC = 1;
    //cin >> TC; 
    FOR(i, 1, TC+1){
        //cout << "Case #" << i << ": ";
        solve();
    }
	
	return 0;
}

Compilation message (stderr)

feast.cpp: In function 'int main()':
feast.cpp:66:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   66 |     freopen("input.txt", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
feast.cpp:67:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   67 |      freopen("output.txt", "w", stdout);
      |      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 8 / 8
• Subtask 3: 18 / 18
• Subtask 4: 10 / 10
• Subtask 5: 11 / 11
• Subtask 6: 20 / 20
• Subtask 7: 29 / 29