【题目链接】:http://codeforces.com/contest/509/problem/A

【题意】



给你一个递推式f[i][j] = f[i-1][j]+f[i][j-1];

让你求f[i][j]的最大值;

【题解】



傻逼题



【Number Of WA】



0



【完整代码】

#include <bits/stdc++.h>

using namespace std;

#define lson l,m,rt<<1

#define rson m+1,r,rt<<1|1

#define LL long long

#define rep1(i,a,b) for (int i = a;i <= b;i++)

#define rep2(i,a,b) for (int i = a;i >= b;i--)

#define mp make_pair

#define ps push_back

#define fi first

#define se second

#define rei(x) cin >> x

#define pri(x) cout << x

#define ms(x,y) memset(x,y,sizeof x)

typedef pair<int,int> pii;

typedef pair<LL,LL> pll;

const int dx[9] = {0,1,-1,0,0,-1,-1,1,1};

const int dy[9] = {0,0,0,-1,1,-1,1,-1,1};

const double pi = acos(-1.0);

const int N = 20;

LL a[N][N],ans;

int n;

int main()

{

    //freopen("F:\\rush.txt","r",stdin);

    ios::sync_with_stdio(false);

    rei(n);

    rep1(i,1,n)

        a[i][1]=a[1][i]=1;

    rep1(i,2,n)

        rep1(j,2,n)

            a[i][j] = a[i-1][j]+a[i][j-1];

    ans = 1;

    rep1(i,1,n)

        rep1(j,1,n)

            ans = max(ans,a[i][j]);

    pri(ans<<endl);

    //printf("\n%.2lf sec \n", (double)clock() / CLOCKS_PER_SEC);

    return 0;

}