Submission #1078326


Source Code Expand

#include <iostream>
#include <fstream>
#include <vector>
#include <stack>
#include <queue>
#include <cstring>
#include <cmath>
#include <cstdlib>
#include <cstdio>
#include <algorithm>
#include <unordered_map>
#include <unordered_set>
#include <map>
#include <set>

using namespace std;

typedef long long ll;
typedef pair<int,int> PP;

/*
    freopen("input","r",stdin);
    freopen("output","w",stdout);
*/

ll MOD = 1E9 + 7;

int main() {
    ios::sync_with_stdio(false);
    int N, M, K;
    cin >> N >> M >> K;
    int st = (N + M - 1) / (K - 1);
    ll A[2010], B[2010];
    memset(A, 0, sizeof(A));
    ll res = 0;
    for (int i = 0;i < K;i++) {
    	A[i] = 1;
    	if (i != 0 && (N - i) % (K - 1) == 0 && (N - i) / (K - 1) < st) res++;
    }
    for (int i = 1;i < st;i++) {
    	int rem = st - i - 1;
    	memset(B, 0, sizeof(B));
    	ll sum = 0;
    	for (int j = 1;j <= N;j++) {
    		sum += A[j - 1];
    		sum %= MOD;
    		// Place 1 ~ K - 1.
    		B[j] = sum;
    		if ((N - j) % (K - 1) == 0 && (N - j) / (K - 1) <= rem) {
    			res += B[j];
    			res %= MOD;
    		}
    		if (j - (K - 1) >= 0) {
    			sum += MOD - A[j - (K - 1)];
    			sum %= MOD;
    		}
    	}
    	// Place 0.
    	for (int j = 0;j <= N;j++) {
    		B[j] += A[j];
    		B[j] %= MOD;
    	}
    	swap(A, B);
    }
    cout << res << endl;
    return 0;
}

Submission Info

Submission Time
Task E - Eternal Average
User ZhusongLi
Language C++14 (GCC 5.4.1)
Score 1600
Code Size 1414 Byte
Status AC
Exec Time 345 ms
Memory 256 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 1600 / 1600
Status
AC × 3
AC × 27
Set Name Test Cases
Sample s1.txt, s2.txt, s3.txt
All 01.txt, 02.txt, 03.txt, 04.txt, 05.txt, 06.txt, 07.txt, 08.txt, 09.txt, 10.txt, 11.txt, 12.txt, 13.txt, 14.txt, 15.txt, 16.txt, 17.txt, 18.txt, 19.txt, 20.txt, 21.txt, 22.txt, 23.txt, 24.txt, s1.txt, s2.txt, s3.txt
Case Name Status Exec Time Memory
01.txt AC 3 ms 256 KB
02.txt AC 345 ms 256 KB
03.txt AC 3 ms 256 KB
04.txt AC 3 ms 256 KB
05.txt AC 169 ms 256 KB
06.txt AC 4 ms 256 KB
07.txt AC 43 ms 256 KB
08.txt AC 3 ms 256 KB
09.txt AC 13 ms 256 KB
10.txt AC 10 ms 256 KB
11.txt AC 3 ms 256 KB
12.txt AC 3 ms 256 KB
13.txt AC 5 ms 256 KB
14.txt AC 3 ms 256 KB
15.txt AC 5 ms 256 KB
16.txt AC 3 ms 256 KB
17.txt AC 3 ms 256 KB
18.txt AC 4 ms 256 KB
19.txt AC 178 ms 256 KB
20.txt AC 47 ms 256 KB
21.txt AC 3 ms 256 KB
22.txt AC 42 ms 256 KB
23.txt AC 8 ms 256 KB
24.txt AC 6 ms 256 KB
s1.txt AC 3 ms 256 KB
s2.txt AC 3 ms 256 KB
s3.txt AC 3 ms 256 KB