#include<bits/stdc++.h>
//#include "peru.h"
using namespace std;
#define ll long long
#define pii pair<int,int>
#define f first
#define s second
#define endl "\n"
const int N = 2e5 + 5, mod = 1e9 + 7; //!
int t;
void add(int &a, int c) {
a += c;
if(a >= mod) a -= mod;
}
int solve(int n, int k, int *x) {
vector<int> a(n + 1), p(n + 1);
vector<ll> dp(n + 1);
for(int i = 0; i < n; i++) a[i + 1] = x[i];
deque<pii> st;
multiset<ll> s;
p[0] = 1;
for(int i = 1; i <= n - 1; i++) p[i] = (ll)p[i - 1] * 23 % mod;
int ans = 0;
for(int i = 1; i <= n; i++) {
dp[i] = 1e15;
int mx = 0;
for(int j = i; j >= max(1, i - k + 1); j--) {
mx = max(mx, a[j]);
dp[i] = min(dp[i], mx + dp[j - 1]);
}
/*
if(st.size() && st.front().s < i - k + 1) {
pii x = st.front();
s.erase(s.find(dp[x.s - 1] + a[x.f]));
st.front().s++;
x.s++;
if(x.s> x.f) st.pop_front();
else s.insert(dp[x.s - 1] + a[x.f]);
}
int l = i;
while(st.size() && a[st.back().f] < a[i]) {
l = st.back().s;
s.erase(s.find(dp[l - 1] + a[st.back().f]));
st.pop_back();
}
st.push_back({i, l});
s.insert(a[i] + dp[l - 1]);
dp[i] = *s.begin();
*/
add(ans, (ll)dp[i] % mod * p[n - i] % mod);
}
return ans;
}
static int s[N];
int main() {
int n, k;
cin >> n >> k;
for(int i = 0; i < n; i++) cin >> s[i];
cout << solve(n, k, s);
}
Compilation message
/usr/bin/ld: /tmp/ccZBfsiv.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccESsaAw.o:peru.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status
