Submission

Score: 150

User: foldnut

Problemset: Chocolate

Language: cpp

Time: 1.089 second

Submitted On: 2026-03-01 22:17:02

#include <bits/stdc++.h>
#define int long long
using namespace std;
const int N = 5e3 + 5, MD = 1e9 + 7;
int n, k, c, l, r, a[N], dp[2][N];
bool can[N][N];

int poww(int b, int ex){
    int res = 1;
    while(ex){
        if(ex & 1){
            res *= b;
            if(res > r) return -1;
        }
        b *= b;
        if(ex != 1 && b > r) return -1;
        ex /= 2;
    }
    return res;
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    cin >> n >> k >> c;
    for(int i = 1;i<=n;i++) cin >> a[i];
    cin >> l >> r;
    for(int i = 1;i<=n;i++){
        int sm = 0;
        for(int j = i;j<=n;j++){
            if(poww(j - i, c) == -1) break;
            sm += poww(j - i, c) * a[j];
            if(sm > r) break;
            if(sm >= l) can[i][j] = 1;
        }
    }
    dp[0][0] = 1;
    for(int i = 1;i<=k;i++){
        for(int j = 0;j<=n;j++) dp[i % 2][j] = 0;
        for(int j = i;j<=n;j++){
            for(int h = j;h>=1;h--){
                if(can[h][j]) dp[i % 2][j] = (dp[i % 2][j] + dp[(i + 1) % 2][h - 1]) % MD;
            }
        }
    }
    cout << dp[k % 2][n];
}