洛谷 P1962 斐波那契数列

题目链接:https://www.luogu.org/problemnew/show/P1962

题目链接:https://www.nowcoder.com/practice/376282a6682a4005973cde7b3df69584?tpId=101&tqId=33251&tPage=1&rp=1&ru=/ta/programmer-code-interview-guide&qru=/ta/programmer-code-interview-guide/question-ranking

题目链接:https://www.nowcoder.com/practice/fd66768dc08748f2be6626f07a02e466?tpId=101&tqId=33252&tPage=1&rp=1&ru=/ta/programmer-code-interview-guide&qru=/ta/programmer-code-interview-guide/question-ranking

题目大意:

  略

分析:

  由于数据规模很大,需要用矩阵快速幂来解。

代码如下:

  1 #include <bits/stdc++.h>
  2 using namespace std;
  3  
  4 #define INIT() ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
  5 #define Rep(i,n) for (int i = 0; i < (int)(n); ++i)
  6 #define For(i,s,t) for (int i = (int)(s); i <= (int)(t); ++i)
  7 #define rFor(i,t,s) for (int i = (int)(t); i >= (int)(s); --i)
  8 #define ForLL(i, s, t) for (LL i = LL(s); i <= LL(t); ++i)
  9 #define rForLL(i, t, s) for (LL i = LL(t); i >= LL(s); --i)
 10 #define foreach(i,c) for (__typeof(c.begin()) i = c.begin(); i != c.end(); ++i)
 11 #define rforeach(i,c) for (__typeof(c.rbegin()) i = c.rbegin(); i != c.rend(); ++i)
 12  
 13 #define pr(x) cout << #x << " = " << x << "  "
 14 #define prln(x) cout << #x << " = " << x << endl
 15  
 16 #define LOWBIT(x) ((x)&(-x))
 17  
 18 #define ALL(x) x.begin(),x.end()
 19 #define INS(x) inserter(x,x.begin())
 20 #define UNIQUE(x) x.erase(unique(x.begin(), x.end()), x.end())
 21 #define REMOVE(x, c) x.erase(remove(x.begin(), x.end(), c), x.end()); // 删去 x 中所有 c 
 22 #define TOLOWER(x) transform(x.begin(), x.end(), x.begin(),::tolower);
 23 #define TOUPPER(x) transform(x.begin(), x.end(), x.begin(),::toupper);
 24  
 25 #define ms0(a) memset(a,0,sizeof(a))
 26 #define msI(a) memset(a,0x3f,sizeof(a))
 27 #define msM(a) memset(a,-1,sizeof(a))
 28 
 29 #define MP make_pair
 30 #define PB push_back
 31 #define ft first
 32 #define sd second
 33  
 34 template<typename T1, typename T2>
 35 istream &operator>>(istream &in, pair<T1, T2> &p) {
 36     in >> p.first >> p.second;
 37     return in;
 38 }
 39  
 40 template<typename T>
 41 istream &operator>>(istream &in, vector<T> &v) {
 42     for (auto &x: v)
 43         in >> x;
 44     return in;
 45 }
 46 
 47 template<typename T>
 48 ostream &operator<<(ostream &out, vector<T> &v) {
 49     Rep(i, v.size()) out << v[i] << " \n"[i == v.size() - 1];
 50     return out;
 51 }
 52  
 53 template<typename T1, typename T2>
 54 ostream &operator<<(ostream &out, const std::pair<T1, T2> &p) {
 55     out << "[" << p.first << ", " << p.second << "]" << "\n";
 56     return out;
 57 }
 58 
 59 inline int gc(){
 60     static const int BUF = 1e7;
 61     static char buf[BUF], *bg = buf + BUF, *ed = bg;
 62     
 63     if(bg == ed) fread(bg = buf, 1, BUF, stdin);
 64     return *bg++;
 65 } 
 66 
 67 inline int ri(){
 68     int x = 0, f = 1, c = gc();
 69     for(; c<48||c>57; f = c=='-'?-1:f, c=gc());
 70     for(; c>47&&c<58; x = x*10 + c - 48, c=gc());
 71     return x*f;
 72 }
 73 
 74 template<class T>
 75 inline string toString(T x) {
 76     ostringstream sout;
 77     sout << x;
 78     return sout.str();
 79 }
 80 
 81 inline int toInt(string s) {
 82     int v;
 83     istringstream sin(s);
 84     sin >> v;
 85     return v;
 86 }
 87 
 88 //min <= aim <= max
 89 template<typename T>
 90 inline bool BETWEEN(const T aim, const T min, const T max) {
 91     return min <= aim && aim <= max;
 92 }
 93 
 94 typedef unsigned int uI;
 95 typedef long long LL;
 96 typedef unsigned long long uLL;
 97 typedef vector< int > VI;
 98 typedef vector< bool > VB;
 99 typedef vector< char > VC;
100 typedef vector< double > VD;
101 typedef vector< string > VS;
102 typedef vector< LL > VL;
103 typedef vector< VI > VVI;
104 typedef vector< VB > VVB;
105 typedef vector< VS > VVS;
106 typedef vector< VL > VVL;
107 typedef vector< VVI > VVVI;
108 typedef vector< VVL > VVVL;
109 typedef pair< int, int > PII;
110 typedef pair< LL, LL > PLL;
111 typedef pair< int, string > PIS;
112 typedef pair< string, int > PSI;
113 typedef pair< string, string > PSS;
114 typedef pair< double, double > PDD;
115 typedef vector< PII > VPII;
116 typedef vector< PLL > VPLL;
117 typedef vector< VPII > VVPII;
118 typedef vector< VPLL > VVPLL;
119 typedef vector< VS > VVS;
120 typedef map< int, int > MII;
121 typedef unordered_map< int, int > uMII;
122 typedef map< LL, LL > MLL;
123 typedef map< string, int > MSI;
124 typedef map< int, string > MIS;
125 typedef set< int > SI;
126 typedef stack< int > SKI;
127 typedef deque< int > DQI;
128 typedef queue< int > QI;
129 typedef priority_queue< int > PQIMax;
130 typedef priority_queue< int, VI, greater< int > > PQIMin;
131 const double EPS = 1e-8;
132 const LL inf = 0x7fffffff;
133 const LL infLL = 0x7fffffffffffffffLL;
134 const LL mod = 1e9 + 7;
135 const int maxN = 1e6 + 7;
136 const LL ONE = 1;
137 const LL evenBits = 0xaaaaaaaaaaaaaaaa;
138 const LL oddBits = 0x5555555555555555;
139 
140 struct Matrix{
141     int row, col;
142     LL MOD;
143     VVL mat;
144     
145     Matrix(int r, int c, LL p = mod) : row(r), col(c), MOD(p) { 
146         mat.assign(r, VL(c, 0));
147     }
148     Matrix(const Matrix &x, LL p = mod) : MOD(p){
149         mat = x.mat;
150         row = x.row;
151         col = x.col;
152     }
153     Matrix(const VVL &A, LL p = mod) : MOD(p){
154         mat = A;
155         row = A.size();
156         col = A[0].size();
157     }
158     
159     // x * 单位阵 
160     inline void E(int x = 1) {
161         assert(row == col);
162         Rep(i, row) mat[i][i] = x;
163     }
164     
165     inline VL& operator[] (int x) {
166         assert(x >= 0 && x < row);
167         return mat[x];
168     }
169     
170     inline Matrix operator= (const VVL &x) {
171         row = x.size();
172         col = x[0].size();
173         mat = x;
174         return *this;
175     }
176     
177     inline Matrix operator+ (const Matrix &x) {
178         assert(row == x.row && col == x.col);
179         Matrix ret(row, col);
180         Rep(i, row) {
181             Rep(j, col) {
182                 ret.mat[i][j] = mat[i][j] + x.mat[i][j];
183                 ret.mat[i][j] %= MOD;
184             }
185         }
186         return ret;
187     }
188     
189     inline Matrix operator* (const Matrix &x) {
190         assert(col == x.row);
191         Matrix ret(row, x.col);
192         Rep(k, x.col) {
193             Rep(i, row) {
194                 if(mat[i][k] == 0) continue;
195                 Rep(j, x.col) {
196                     ret.mat[i][j] += mat[i][k] * x.mat[k][j];
197                     ret.mat[i][j] %= MOD;
198                 }
199             }
200         }
201         return ret;
202     }
203     
204     inline Matrix operator*= (const Matrix &x) { return *this = *this * x; }
205     inline Matrix operator+= (const Matrix &x) { return *this = *this + x; }
206 };
207 
208 // 矩阵快速幂,计算x^y 
209 inline Matrix mat_pow_mod(Matrix x, LL y) {
210     Matrix ret(x.row, x.col);
211     ret.E();
212     while(y){
213         if(y & 1) ret *= x;
214         x *= x;
215         y >>= 1;
216     }
217     return ret;
218 }
219 
220 LL N; 
221 Matrix ans(VVL({{1, 1}, {1, 0}}));
222 
223 int main(){
224     //freopen("MyOutput.txt","w",stdout);
225     //freopen("input.txt","r",stdin);
226     //INIT();
227     scanf("%lld", &N);
228     ans = mat_pow_mod(ans, N);
229     printf("%lld\n", ans.mat[0][1]);
230     return 0;
231 }
View Code

 

posted @ 2019-04-28 00:47  梦樱羽  阅读(238)  评论(0编辑  收藏  举报
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