Submission #3955540


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#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)
#define fore(i,a) for(auto &i:a)
#define all(x) (x).begin(),(x).end()
//#pragma GCC optimize ("-O3")
using namespace std; void _main(); int main() { cin.tie(0); ios::sync_with_stdio(false); _main(); }
typedef long long ll; const int inf = INT_MAX / 2; const ll infl = 1LL << 60;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a = b; return 1; } return 0; }
//---------------------------------------------------------------------------------------------------
typedef long long ll;
int mod = 1000000007;
int add(int x, int y) { return (x += y) >= mod ? x - mod : x; }
template<class... T> int add(int x, T... y) { return add(x, add(y...)); }
int mul(int x, int y) { return 1LL * x * y % mod; }
template<class... T> int mul(int x, T... y) { return mul(x, mul(y...)); }
int sub(int x, int y) { return add(x, mod - y); }
int modpow(int a, long long b) {
    int ret = 1; while (b > 0) {
        if (b & 1) ret = 1LL * ret * a % mod; a = 1LL * a * a % mod; b >>= 1;
    } return ret;
}
int modinv(int a) { return modpow(a, mod - 2); }
typedef vector<int> Vec;
typedef vector<Vec> Mat;
Vec mulMatVec(Mat a, Vec b)
{
    int n = b.size(); Vec ret(n, 0);
    rep(i, 0, n) rep(j, 0, n) ret[i] = add(ret[i], mul(a[i][j], b[j]));
    return ret;
}
Mat mulMatMat(Mat a, Mat b)
{
    int n = a.size(); Mat ret(n, Vec(n, 0));
    rep(i, 0, n) rep(j, 0, n) rep(k, 0, n) ret[i][j] = add(ret[i][j], mul(a[i][k], b[k][j]));
    return ret;
}
Mat fastpow(Mat x, ll n)
{
    Mat ret(x.size(), Vec(x.size(), 0));
    rep(i, 0, x.size()) ret[i][i] = 1;
    while (0 < n) { if ((n % 2) == 0) { x = mulMatMat(x, x); n >>= 1; } else { ret = mulMatMat(ret, x); --n; } }
    return ret;
}
void printVec(Vec a) { cout << "[\t"; rep(i, 0, a.size()) cout << a[i] << "\t"; cout << "]" << endl; }
void printMat(Mat a) { rep(i, 0, a.size()) printVec(a[i]); }
/*---------------------------------------------------------------------------------------------------
            ∧_∧  
      ∧_∧  (´<_` )  Welcome to My Coding Space!
     ( ´_ゝ`) /  ⌒i     
    /   \     | |     
    /   / ̄ ̄ ̄ ̄/  |  
  __(__ニつ/     _/ .| .|____  
     \/____/ (u ⊃  
---------------------------------------------------------------------------------------------------*/












int N; ll K; int A[50][50];
//---------------------------------------------------------------------------------------------------
void _main() {
    cin >> N >> K;
    rep(i, 0, N) rep(j, 0, N) cin >> A[i][j];

    Mat m(N, Vec(N, 0));
    Vec v(N, 1);

    rep(i, 0, N) rep(j, 0, N) m[i][j] = A[i][j];
    m = fastpow(m, K);
    v = mulMatVec(m, v);

    ll ans = 0;
    rep(i, 0, N) ans += v[i];
    ans %= mod;
    cout << ans << endl;
}

Submission Info

Submission Time
Task R - Walk
User hamayanhamayan
Language C++14 (GCC 5.4.1)
Score 100
Code Size 3128 Byte
Status AC
Exec Time 169 ms
Memory 384 KB

Judge Result

Set Name All
Score / Max Score 100 / 100
Status
AC × 23
Set Name Test Cases
All 0_00, 0_01, 0_02, 0_03, 0_04, 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, 1_14, 1_15, 1_16, 1_17
Case Name Status Exec Time Memory
0_00 AC 1 ms 256 KB
0_01 AC 1 ms 256 KB
0_02 AC 1 ms 256 KB
0_03 AC 1 ms 256 KB
0_04 AC 2 ms 256 KB
1_00 AC 1 ms 256 KB
1_01 AC 1 ms 256 KB
1_02 AC 3 ms 384 KB
1_03 AC 118 ms 384 KB
1_04 AC 4 ms 384 KB
1_05 AC 120 ms 384 KB
1_06 AC 3 ms 384 KB
1_07 AC 169 ms 384 KB
1_08 AC 88 ms 384 KB
1_09 AC 120 ms 384 KB
1_10 AC 123 ms 384 KB
1_11 AC 112 ms 384 KB
1_12 AC 108 ms 384 KB
1_13 AC 136 ms 384 KB
1_14 AC 125 ms 384 KB
1_15 AC 128 ms 384 KB
1_16 AC 130 ms 384 KB
1_17 AC 129 ms 384 KB