Submission #485968

#	Time	Username	Problem	Language	Result	Execution time	Memory
485968		MilosMilutinovic	K blocks (IZhO14_blocks)	C++14	100 / 100	239 ms	84472 KiB

blocks

#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,n) for (int i=a;i<n;i++)
#define per(i,a,n) for (int i=n-1;i>=a;i--)
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define SZ(x) ((int)(x).size())
typedef vector<int> VI;
typedef long long ll;
typedef pair<int,int> PII;
typedef double db;
mt19937 mrand(random_device{}()); 
const ll mod=1000000007;
const ll mod2=998244353;
int rnd(int x) { return mrand() % x;}
ll powmod(ll a,ll b) {ll res=1;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
ll gcd(ll a,ll b) { return b?gcd(b,a%b):a;}
// head

const int N=1010000;
int n,k,a[N];
ll dp[N][105];

int main() {
	scanf("%d%d",&n,&k);
	rep(i,1,n+1) scanf("%d",a+i);
	rep(i,0,105) rep(j,0,n+1) dp[i][j]=(1LL<<40);
	int mx=0;
	rep(i,1,n+1) {
		mx=max(mx,a[i]);
		dp[i][1]=mx;
	}
	rep(j,2,k+1) {
		stack<pair<ll,ll>> stk;
		rep(i,1,n+1) {
			ll ft=dp[i-1][j-1];
			while (SZ(stk)&&stk.top().fi<a[i]) ft=min(ft,stk.top().se),stk.pop();
			if (stk.empty()||a[i]+ft<stk.top().fi+stk.top().se) stk.push(mp(a[i],ft));
			if (i>=j) dp[i][j]=stk.top().fi+stk.top().se;
		}
	}
	printf("%lld",dp[n][k]);
}

Compilation message (stderr)

blocks.cpp: In function 'int main()':
blocks.cpp:28:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 |  scanf("%d%d",&n,&k);
      |  ~~~~~^~~~~~~~~~~~~~
blocks.cpp:29:20: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |  rep(i,1,n+1) scanf("%d",a+i);
      |               ~~~~~^~~~~~~~~~

• Subtask 1: 14 / 14
• Subtask 2: 18 / 18
• Subtask 3: 21 / 21
• Subtask 4: 47 / 47