Submission #3962656

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#include <bits/stdc++.h>
using namespace std;

#define NDEBUG
#include <cassert>


typedef long long ll;
typedef long double Double;
typedef unsigned long long ull;
typedef pair<int,int> ii;
typedef pair<ll,ll> llll;
typedef pair<double,double> dd;

typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef vector<ii> vii;
typedef vector<vector<ii>> vvii;
typedef vector<ll> vll;
typedef vector<vector<ll>> vvll;
typedef vector<llll> vllll;
typedef vector<bool> vb;
typedef vector<string> vs;
typedef vector<double> vd;
typedef vector<long double> vD;

#define sz(a)  int((a).size())
#define pb  push_back
#define eb  emplace_back
#define FOR(var,from,to) for(int var=(from);var<=(to);++var)
#define rep(var,n)  for(int var=0;var<(n);++var)
#define rep1(var,n)  for(int var=1;var<=(n);++var)
#define repC2(vari,varj,n)  for(int vari=0;vari<(n)-1;++vari)for(int varj=vari+1;varj<(n);++varj)
#define repC3(vari,varj,vark,n)  for(int vari=0;vari<(n)-2;++vari)for(int varj=vari+1;varj<(n)-1;++varj)for(int vark=varj+1;vark<(n);++vark)
#define ALL(c)  (c).begin(),(c).end()
#define RALL(c)  (c).rbegin(),(c).rend()
#define tr(i,c)  for(auto i=(c).begin(); i!=(c).end(); ++i)
#define found(s,e)  ((s).find(e)!=(s).end())
#define mset(arr,val)  memset(arr,val,sizeof(arr))
#define mid(x,y) ((x)+((y)-(x))/2)
#define IN(x,a,b) ((a)<=(x)&&(x)<=(b))
#define cons make_pair

template<class T> inline void amin(T & a, T const & b) { a = min(a, b); }
template<class T> inline void amax(T & a, T const & b) { a = max(a, b); }
template<typename X, typename T> auto vectors(X x, T a) { return vector<T>(x, a); }
template<typename X, typename Y, typename Z, typename... Zs> auto vectors(X x, Y y, Z z, Zs... zs) { auto cont = vectors(y, z, zs...); return vector<decltype(cont)>(x, cont); }


ll gcd(ll a, ll b) { while(a) swap(a, b%=a); return b; }

const ll MOD=1000000007LL;

ll ADD(ll x, ll y) { return (x+y) % MOD; }
ll SUB(ll x, ll y) { return (x-y+MOD) % MOD; }
ll MUL(ll x, ll y) { return x*y % MOD; }
ll POW(ll x, ll e) { ll v=1; for(; e; x=MUL(x,x), e>>=1) if (e&1) v = MUL(v,x); return v; }
ll DIV(ll x, ll y) { /*assert(y%MOD!=0);*/ return MUL(x, POW(y, MOD-2)); }


ll solve(int N, string& s) {
    vll ac(N*2+1, 0);
    int lo = N, hi = N;
    ac[lo] = 1;
    for (int i=0; i<N-1; ++i) {
        if (s[i] == '<') {
            for (int j=lo; j<=hi; ++j) {
                (ac[j] += ac[j-1]) %= MOD;
            }
            --lo;
        } else {
            for (int j=hi; j>=lo; --j) {
                (ac[j] += ac[j+1]) %= MOD;
            }
            ++hi;
        }
    }

    return accumulate(ALL(ac), 0LL) % MOD;
}

int main() {
    int N; cin >> N;
    string s; cin >> s;
    assert(s.size() == N-1);
    cout << solve(N,s) << endl;
    return 0;
}

Submission Info

Submission Time
Task T - Permutation
User naoya_t
Language C++14 (GCC 5.4.1)
Score 100
Code Size 2854 Byte
Status
Exec Time 28 ms
Memory 256 KB

Test Cases

Set Name Score / Max Score Test Cases
All 100 / 100 0_00, 0_01, 0_02, 1_00, 1_01, 1_02, 1_03, 1_04, 1_05, 1_06, 1_07, 1_08, 1_09, 1_10, 1_11, 1_12, 1_13
Case Name Status Exec Time Memory
0_00 1 ms 256 KB
0_01 1 ms 256 KB
0_02 1 ms 256 KB
1_00 1 ms 256 KB
1_01 1 ms 256 KB
1_02 28 ms 256 KB
1_03 28 ms 256 KB
1_04 28 ms 256 KB
1_05 28 ms 256 KB
1_06 28 ms 256 KB
1_07 27 ms 256 KB
1_08 27 ms 256 KB
1_09 28 ms 256 KB
1_10 27 ms 256 KB
1_11 27 ms 256 KB
1_12 26 ms 256 KB
1_13 28 ms 256 KB