题意:求A + A^2 + A^3 + ... + A^m。
析:主要是两种方式,第一种是倍增法,把A + A^2 + A^3 + ... + A^m,拆成两部分,一部分是(E + A^(m/2))(A + A^2 + A^3 + ... + A^(m/2)),然后依次计算下去,就可以分解,logn的复杂度分解,注意要分奇偶。
另一种是直接构造矩阵,,然后就可以用辞阵快速幂计算了,注意要用分块矩阵的乘法。
代码如下:
倍增法:
#pragma comment(linker, "/STACK:1024000000,1024000000") #include <cstdio> #include <string> #include <cstdlib> #include <cmath> #include <iostream> #include <cstring> #include <set> #include <queue> #include <algorithm> #include <vector> #include <map> #include <cctype> #include <cmath> #include <stack> #include <sstream> #include <list> #define debug() puts("++++"); #define gcd(a, b) __gcd(a, b) #define lson l,m,rt<<1 #define rson m+1,r,rt<<1|1 #define freopenr freopen("in.txt", "r", stdin) #define freopenw freopen("out.txt", "w", stdout) using namespace std; typedef long long LL; typedef unsigned long long ULL; typedef pair<int, int> P; const int INF = 0x3f3f3f3f; const double inf = 0x3f3f3f3f3f3f; const double PI = acos(-1.0); const double eps = 1e-8; const int maxn = 1e3 + 10; const int mod = 10; const int dr[] = {-1, 0, 1, 0}; const int dc[] = {0, 1, 0, -1}; const char *de[] = {"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"}; int n, m; const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; const int monn[] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; inline bool is_in(int r, int c) { return r > 0 && r <= n && c > 0 && c <= m; } struct Matrix{ int a[40][40]; int n; friend Matrix operator + (const Matrix &lhs, const Matrix &rhs){ Matrix res; res.n = lhs.n; for(int i = 0; i < lhs.n; ++i) for(int j = 0; j < lhs.n; ++j) res.a[i][j] = (lhs.a[i][j] + rhs.a[i][j]) % mod; return res; } friend Matrix operator * (const Matrix &lhs, const Matrix &rhs){ Matrix res; res.n = lhs.n; for(int i = 0; i < lhs.n; ++i) for(int j = 0; j < lhs.n; ++j){ res.a[i][j] = 0; for(int k = 0; k < lhs.n; ++k) res.a[i][j] += lhs.a[i][k] * rhs.a[k][j]; res.a[i][j] %= mod; } return res; } }; Matrix E; Matrix fast_pow(Matrix a, int m){ Matrix res; res.n = n; memset(res.a, 0, sizeof res.a); for(int i = 0; i < res.n; ++i) res.a[i][i] = 1; while(m){ if(m & 1) res = res * a; m >>= 1; a = a * a; } return res; } Matrix dfs(int m, Matrix x){ if(m == 1) return x; if(m == 0) return E; Matrix ans = (E + fast_pow(x, m/2)) * dfs(m/2, x); if(m & 1) ans = ans + fast_pow(x, m); return ans; } int main(){ while(scanf("%d %d", &n, &m) == 2 && n){ Matrix x; x.n = n; E.n = n; memset(E.a, 0, sizeof E.a); for(int i = 0; i < n; ++i) E.a[i][i] = 1; for(int i = 0; i < n; ++i) for(int j = 0; j < n; ++j){ scanf("%d", &x.a[i][j]); x.a[i][j] %= mod; } Matrix ans = dfs(m, x); for(int i = 0; i < n; ++i) for(int j = 0; j < n; ++j) if(j + 1 == n) printf("%d\n", ans.a[i][j]); else printf("%d ", ans.a[i][j]); printf("\n"); } return 0; }
构造法:
#pragma comment(linker, "/STACK:1024000000,1024000000") #include <cstdio> #include <string> #include <cstdlib> #include <cmath> #include <iostream> #include <cstring> #include <set> #include <queue> #include <algorithm> #include <vector> #include <map> #include <cctype> #include <cmath> #include <stack> #include <sstream> #include <list> #define debug() puts("++++"); #define gcd(a, b) __gcd(a, b) #define lson l,m,rt<<1 #define rson m+1,r,rt<<1|1 #define freopenr freopen("in.txt", "r", stdin) #define freopenw freopen("out.txt", "w", stdout) using namespace std; typedef long long LL; typedef unsigned long long ULL; typedef pair<int, int> P; const int INF = 0x3f3f3f3f; const double inf = 0x3f3f3f3f3f3f; const double PI = acos(-1.0); const double eps = 1e-8; const int maxn = 1e3 + 10; const int mod = 10; const int dr[] = {-1, 0, 1, 0}; const int dc[] = {0, 1, 0, -1}; const char *de[] = {"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"}; int n, m; const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; const int monn[] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; inline bool is_in(int r, int c) { return r > 0 && r <= n && c > 0 && c <= m; } struct Node{ int a[80][80]; friend void add(const Node &lhs, const Node &rhs, Node &res, int x, int y, int l, int r){ for(int i = x; i < y; ++i) for(int j = l; j < r; ++j) res.a[i][j] = (lhs.a[i-x][j-l] + rhs.a[i-x][j-l]) % mod; } friend void solve(int x, int y, int l, int r, int p, int q, const Node &lhs, const Node &rhs, Node &res){ for(int i = x; i < y; ++i) for(int j = l; j < r; ++j){ res.a[i-x][j-l] = 0; for(int k = p; k < q; ++k) res.a[i-x][j-l] += lhs.a[i][k] * rhs.a[k][j]; } } friend Node operator * (const Node &lhs, const Node &rhs){ Node res, x, y; solve(0, n, 0, n, 0, n, lhs, rhs, x); solve(0, n, 0, n, n, n+n, lhs, rhs, y); add(x, y, res, 0, n, 0, n); solve(0, n, n, n+n, 0, n, lhs, rhs, x); solve(0, n, n, n+n, n, n+n, lhs, rhs, y); add(x, y, res, 0, n, n, n+n); solve(n, n+n, 0, n, 0, n, lhs, rhs, x); solve(n, n+n, 0, n, n, n+n, lhs, rhs, y); add(x, y, res, n, n+n, 0, n); solve(n, n+n, n, n+n, 0, n, lhs, rhs, x); solve(n, n+n, n, n+n, n, n+n, lhs, rhs, y); add(x, y, res, n, n+n, n, n+n); return res; } }; Node fast_pow(Node a, int m){ Node res; memset(res.a, 0, sizeof res.a); for(int i = 0; i < n; ++i) res.a[i][i] = res.a[i+n][i] = 1; while(m){ if(m & 1) res = res * a; m >>= 1; a = a * a; } return res; } int main(){ while(scanf("%d %d", &n, &m) == 2 && n){ Node x, y; memset(y.a, 0, sizeof y.a); for(int i = 0; i < n; ++i) for(int j = n; j < n+n; ++j){ scanf("%d", &y.a[i][j]); y.a[i][j] %= mod; } for(int i = 0; i < n; ++i) y.a[i][i] = 1; for(int i = n; i < n + n; ++i) for(int j = n; j < n + n; ++j) y.a[i][j] = y.a[i-n][j]; memset(x.a, 0, sizeof x.a); for(int i = n; i < n+n; ++i) x.a[i][i-n] = 1; Node ans = fast_pow(y, m); if(m) ans = ans * x; for(int i = 0; i < n; ++i) for(int j = 0; j < n; ++j) if(j == n-1) printf("%d\n", ans.a[i][j]); else printf("%d ", ans.a[i][j]); printf("\n"); } return 0; }