Submission #1000862

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Source Code Expand

#include <bits/stdc++.h>
#define SZ(X) ((int)(X).size())
#define ALL(X) (X).begin(), (X).end()
#define REP(I, N) for (int I = 0; I < (N); ++I)
#define REPP(I, A, B) for (int I = (A); I < (B); ++I)
#define RI(X) scanf("%d", &(X))
#define RII(X, Y) scanf("%d%d", &(X), &(Y))
#define RIII(X, Y, Z) scanf("%d%d%d", &(X), &(Y), &(Z))
#define DRI(X) int (X); scanf("%d", &X)
#define DRII(X, Y) int X, Y; scanf("%d%d", &X, &Y)
#define DRIII(X, Y, Z) int X, Y, Z; scanf("%d%d%d", &X, &Y, &Z)
#define RS(X) scanf("%s", (X))
#define CASET int ___T, case_n = 1; scanf("%d ", &___T); while (___T-- > 0)
#define MP make_pair
#define PB push_back
#define MS0(X) memset((X), 0, sizeof((X)))
#define MS1(X) memset((X), -1, sizeof((X)))
#define LEN(X) strlen(X)
#define PII pair<int,int>
#define VI vector<int>
#define VPII vector<pair<int,int> >
#define PLL pair<long long,long long>
#define VPLL vector<pair<long long,long long> >
#define F first
#define S second
typedef long long LL;
using namespace std;
const int MOD = 1e9+7;
const int SIZE = 1e6+10;
LL fac[SIZE],inv[SIZE];
LL mypow(LL x,LL y){
    LL res=1;
    while(y){
        if(y&1)res=res*x%MOD;
        y>>=1;
        x=x*x%MOD;
    }
    return res;
}
LL CC(int x,int y){
    if(y<0||y>x)return 0;
    return fac[x]*inv[y]%MOD*inv[x-y]%MOD;
}
void build(){
    assert(MOD>=SIZE);
    fac[0]=1;
    REPP(i,1,SIZE)fac[i]=fac[i-1]*i%MOD;
    inv[SIZE-1]=mypow(fac[SIZE-1],MOD-2);
    for(int i=SIZE-2;i>=0;i--)inv[i]=inv[i+1]*(i+1)%MOD;
}
LL dp[5001][5001];
void ADD(LL& x,LL v){x=(x+v)%MOD;}
int main(){
    build();
    DRI(N);
    DRIII(A,B,C);
    if(B%2)return 0*puts("0");
    MS1(dp);
    LL base=CC(A+B/2,A),an=0;
    if(B){
        REP(i,C+1)REP(j,C-i+1){
            if((C-i-j)%3)continue;
            ADD(an,CC(A,i)*CC(A+B/2+(C-i-j)/3,(C-i-j)/3)%MOD*CC(B/2+j-1,j));
        }
    }
    else{
        REP(i,C+1){
            int j=0;
            if((C-i-j)%3)continue;
            ADD(an,CC(A,i)*CC(A+B/2+(C-i-j)/3,(C-i-j)/3));
        }
    }
    cout<<an*base%MOD<<endl;
    return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:55:11: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     DRI(N);
           ^
./Main.cpp:56:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     DRIII(A,B,C);
                 ^

Judge Result