#include <bits/stdc++.h>
#define x first
#define y second
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
const ll INF = 1e18;
const int N = 25e5 + 10;
const int MOD = 1e9 + 7;
struct obj{
ll sum;
int arr;
int ind;
};
int cntb = 0;
ll dp[N];
deque<obj> d;
stack<ll> l, r;
int add(ll a, ll b){
return (a + b) % MOD;
}
int mult(ll a, ll b){
return a * b % MOD;
}
ll opt(){
ll ret = INF;
if(!l.empty()) ret = min(ret, l.top());
if(!r.empty()) ret = min(ret, r.top());
return ret;
}
void push(stack<ll> &s, ll val){
if(s.empty()) s.push(val);
else s.push(min(val, s.top()));
}
void build(){
while(!l.empty()) l.pop();
while(!r.empty()) r.pop();
int siz = d.size();
int m = d.size() / 2;
vector<obj> v;
for(int i = 0; i < m; i++){
v.push_back(d.front());
d.pop_front();
}
while(!v.empty()){
push(l, v.back().sum);
d.push_front(v.back());
v.pop_back();
}
for(int i = 0; i < siz - m; i++){
v.push_back(d.back());
d.pop_back();
}
while(!v.empty()){
push(r, v.back().sum);
d.push_back(v.back());
v.pop_back();
}
}
obj getobj(ll sum, int arr, int ind){
obj ret;
ret.sum = sum;
ret.arr = arr;
ret.ind = ind;
return ret;
}
int solve(int n, int k, int* arr){
for(int i = 1; i <= n; i++){
if(i == 1){
dp[i] = arr[i - 1];
d.push_back(getobj(dp[i - 1] + arr[i - 1], arr[i - 1], i));
push(r, dp[i - 1] + arr[i - 1]);
} else {
int dpind = i;
while(!d.empty() && d.back().arr <= arr[i - 1]){
dpind = d.back().ind;
d.pop_back();
if(r.empty()) build();
else r.pop();
}
d.push_back(getobj(dp[dpind - 1] + arr[i - 1], arr[i - 1], dpind));
push(r, dp[dpind - 1] + arr[i - 1]);
if(i > k){
ll arrmax = d.front().arr;
if(d.front().ind <= i - k){
d.pop_front();
if(l.empty()) build();
else l.pop();
if(d.empty()){
d.push_front(getobj(dp[i - k] + arrmax, arrmax, i - k + 1));
push(l, dp[i - k] + arrmax);
} else if(d.front().ind > i - k + 1){
d.push_front(getobj(dp[i - k] + arrmax, arrmax, i - k + 1));
push(l, dp[i - k] + arrmax);
}
}
}
dp[i] = opt();
}
}
for(int i = 1; i <= n; i++) dp[i] %= MOD;
ll ans = 0, m = 1;
for(int i = n; i > 0; i--){
ans = add(ans, mult(dp[i], m));
m = mult(m, 23);
}
return ans;
}
int main(){
int n, k;
scanf("%d%d", &n, &k);
int arr[n];
for(int i = 0; i < n; i++) scanf("%d", &arr[i]);
printf("%d\n", solve(n, k, arr));
return 0;
}
Compilation message
peru.cpp: In function 'int main()':
peru.cpp:132:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
132 | scanf("%d%d", &n, &k);
| ~~~~~^~~~~~~~~~~~~~~~
peru.cpp:134:34: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
134 | for(int i = 0; i < n; i++) scanf("%d", &arr[i]);
| ~~~~~^~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/cc7d6jH3.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccNF8Gw3.o:peru.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status
