Submission #4255962


Source Code Expand

#include<stdio.h>
#include<iostream>
#include<vector>
#include<algorithm>
#include<string>
#include<string.h>
using namespace std;

typedef long long LL;
typedef vector<int> VI;

#define REP(i,n) for(int i=0, i##_len=(n); i<i##_len; ++i)
#define EACH(i,c) for(__typeof((c).begin()) i=(c).begin(),i##_end=(c).end();i!=i##_end;++i)
#define eprintf(...) fprintf(stderr, __VA_ARGS__)

template<class T> inline void amin(T &x, const T &y) { if (y<x) x=y; }
template<class T> inline void amax(T &x, const T &y) { if (x<y) x=y; }
template<class Iter> void rprintf(const char *fmt, Iter begin, Iter end) {
    for (bool sp=0; begin!=end; ++begin) { if (sp) putchar(' '); else sp = true; printf(fmt, *begin); }
    putchar('\n');
}

template<unsigned MOD> struct ModInt {
    static const unsigned static_MOD = MOD;
    unsigned x;
    void undef() { x = (unsigned)-1; }
    bool isnan() const { return x == (unsigned)-1; }
    inline int geti() const { return (int)x; }
    ModInt() { x = 0; }
    ModInt(const ModInt &y) { x = y.x; }
    ModInt(int y) { if (y<0 || (int)MOD<=y) y %= (int)MOD; if (y<0) y += MOD; x=y; }
    ModInt(unsigned y) { if (MOD<=y) x = y % MOD; else x = y; }
    ModInt(long long y) { if (y<0 || MOD<=y) y %= MOD; if (y<0) y += MOD; x=y; }
    ModInt(unsigned long long y) { if (MOD<=y) x = y % MOD; else x = y; }
    ModInt &operator+=(const ModInt y) { if ((x += y.x) >= MOD) x -= MOD; return *this; }
    ModInt &operator-=(const ModInt y) { if ((x -= y.x) & (1u<<31)) x += MOD; return *this; }
    ModInt &operator*=(const ModInt y) { x = (unsigned long long)x * y.x % MOD; return *this; }
    ModInt &operator/=(const ModInt y) { x = (unsigned long long)x * y.inv().x % MOD; return *this; }
    ModInt operator-() const { return (x ? MOD-x: 0); }

    ModInt inv() const {
	unsigned a = MOD, b = x; int u = 0, v = 1;
	while (b) {
	    int t = a / b;
	    a -= t * b; swap(a, b);
	    u -= t * v; swap(u, v);
	}
	if (u < 0) u += MOD;
	return ModInt(u);
    }
    ModInt pow(long long y) const {
	ModInt b = *this, r = 1;
	if (y < 0) { b = b.inv(); y = -y; }
	for (; y; y>>=1) {
	    if (y&1) r *= b;
	    b *= b;
	}
	return r;
    }
    friend ModInt operator+(ModInt x, const ModInt y) { return x += y; }
    friend ModInt operator-(ModInt x, const ModInt y) { return x -= y; }
    friend ModInt operator*(ModInt x, const ModInt y) { return x *= y; }
    friend ModInt operator/(ModInt x, const ModInt y) { return x *= y.inv(); }
    friend bool operator<(const ModInt x, const ModInt y) { return x.x < y.x; }
    friend bool operator==(const ModInt x, const ModInt y) { return x.x == y.x; }
    friend bool operator!=(const ModInt x, const ModInt y) { return x.x != y.x; }
};

const LL MOD = 1000000007;
//const LL MOD = 998244353;
typedef ModInt<MOD> Mint;
int N, M, K;
Mint dp[4011][4011];

void MAIN() {
    scanf("%d%d%d", &N, &M, &K);
    dp[0][0] = 1;

    int LEN = (N+M-1) / (K-1);
    dp[0][0] = 1;
    REP (i, LEN) {
	Mint s = 0;
	REP (m, M+1) {
	    s += dp[i][m];
	    if (m >= K) s -= dp[i][m-K];
	    dp[i+1][m] += s;
	}
    }

    Mint ans = 0;
    for (int i=0; i*(K-1)<M; i++) {
	ans += dp[LEN-i][M-i*(K-1)];
    }
    printf("%d\n", ans.geti());
}

int main() {
    int TC = 1;
//    scanf("%d", &TC);
    REP (tc, TC) MAIN();
    return 0;
}

Submission Info

Submission Time
Task E - Eternal Average
User natsugiri
Language C++14 (GCC 5.4.1)
Score 1600
Code Size 3388 Byte
Status AC
Exec Time 47 ms
Memory 63104 KB

Compile Error

./Main.cpp: In function ‘void MAIN()’:
./Main.cpp:76:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%d", &N, &M, &K);
                                ^

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 25 ms 63104 KB
02.txt AC 47 ms 63104 KB
03.txt AC 25 ms 63104 KB
04.txt AC 25 ms 63104 KB
05.txt AC 37 ms 63104 KB
06.txt AC 29 ms 63104 KB
07.txt AC 25 ms 63104 KB
08.txt AC 25 ms 63104 KB
09.txt AC 26 ms 63104 KB
10.txt AC 26 ms 63104 KB
11.txt AC 25 ms 63104 KB
12.txt AC 25 ms 63104 KB
13.txt AC 25 ms 63104 KB
14.txt AC 25 ms 63104 KB
15.txt AC 25 ms 63104 KB
16.txt AC 25 ms 63104 KB
17.txt AC 25 ms 63104 KB
18.txt AC 26 ms 63104 KB
19.txt AC 26 ms 63104 KB
20.txt AC 28 ms 63104 KB
21.txt AC 25 ms 63104 KB
22.txt AC 28 ms 63104 KB
23.txt AC 25 ms 63104 KB
24.txt AC 26 ms 63104 KB
s1.txt AC 25 ms 63104 KB
s2.txt AC 25 ms 63104 KB
s3.txt AC 26 ms 63104 KB