#include<bits/stdc++.h>
#define MAXN 400007
#define INF 1e16
using namespace std;
int n,k;
long long s[MAXN],res;
const long long mod=1000000007;
bool li[MAXN];
long long dp[MAXN];
bool u[MAXN][20];
long long ans[MAXN][20];
int power[20],lg[MAXN];
void calc(){
power[0]=1;
for(int i=1;i<20;i++)power[i]=power[i-1]*2;
lg[1]=0;
for(int i=2;i<MAXN;i++)lg[i]=lg[i/2]+1;
}
long long rmq(int i,int j){
if(j==0)return s[i];
if(u[i][j])return ans[i][j];
u[i][j]=true;
ans[i][j]=max(rmq(i,j-1),rmq(i+power[j-1],j-1));
return ans[i][j];
}
long long getmax(int l,int r){
return max( rmq(l,lg[r-l+1]) , rmq(r-power[lg[r-l+1]]+1,lg[r-l+1]) );
}
long long ff(int n){
if(n==0)return 0;
if(li[n])return dp[n];
li[n]=true;
dp[n]=INF;
for(int i=n;i>=max(1,n-k+1);i--){
dp[n]=min(dp[n],getmax(i,n)+ff(i-1));
}
return dp[n];
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin>>n>>k;
for(int i=1;i<=n;i++){
cin>>s[i];
}
calc();
for(int i=1;i<=n;i++){
res*=23;res+=ff(i);
res%=mod;
}
cout<<res<<"\n";
return 0;
}
Compilation message
/usr/bin/ld: /tmp/cc9cGFrG.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/cc1nn7tG.o:peru.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/cc9cGFrG.o: in function `main':
grader.cpp:(.text.startup+0x144): undefined reference to `solve(int, int, int*)'
collect2: error: ld returned 1 exit status
