Commit f680c87

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added fibonacci number calculation in o(log(n))

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	`1`	`+#include<bits/stdc++.h>`
	`2`	`+using namespace std;`
	`3`	`+`
	`4`	`+typedef long long ll;`
	`5`	`+const int S = 2;`
	`6`	`+const int MOD = 1000000000+7;`
	`7`	`+const int MODQ = 1000000000+7-1;`
	`8`	`+`
	`9`	`+struct mat_t {`
	`10`	`+ int m[S][S];`
	`11`	`+};`
	`12`	`+`
	`13`	`+// Function to calculate matrix multiplication`
	`14`	`+mat_t mat_mult(mat_t& a, mat_t& b) {`
	`15`	`+ mat_t c;`
	`16`	`+`
	`17`	`+ for(int i=0; i<S; i++)`
	`18`	`+ for(int j=0; j<S; j++)`
	`19`	`+ c.m[i][j] = 0;`
	`20`	`+`
	`21`	`+ for(int i=0; i<S; i++) {`
	`22`	`+ for(int k=0; k<S; k++) {`
	`23`	`+ for(int j=0; j<S; j++) {`
	`24`	`+ c.m[i][j] = (c.m[i][j]+ ll(a.m[i][k])*b.m[k][j] % MODQ) % MODQ;`
	`25`	`+ }`
	`26`	`+ }`
	`27`	`+ }`
	`28`	`+`
	`29`	`+ return c;`
	`30`	`+}`
	`31`	`+`
	`32`	`+`
	`33`	`+// Calculation Matrix Power in O(log(n)) ie A^n(where A is matrix)`
	`34`	`+// same as exponentiation power`
	`35`	`+mat_t mat_pow(mat_t a, int n) {`
	`36`	`+ mat_t w;`
	`37`	`+`
	`38`	`+ for(int i=0; i<S; i++) {`
	`39`	`+ for(int j=0; j<S; j++)`
	`40`	`+ w.m[i][j] = i==j;`
	`41`	`+ }`
	`42`	`+`
	`43`	`+`
	`44`	`+ while(n) {`
	`45`	`+ if(n&1) w = mat_mult(w, a);`
	`46`	`+ a = mat_mult(a, a);`
	`47`	`+ n/=2;`
	`48`	`+ }`
	`49`	`+`
	`50`	`+ return w;`
	`51`	`+}`
	`52`	`+`
	`53`	`+`
	`54`	`+int main() {`
	`55`	`+ int n; cin >> n;`
	`56`	`+`
	`57`	`+`
	`58`	`+ mat_t m;`
	`59`	`+ m.m[0][0] = m.m[0][1] = m.m[1][0] = 1;`
	`60`	`+ m.m[1][1] = 0;`
	`61`	`+`
	`62`	`+ m = mat_pow(m, n);`
	`63`	`+ cout << m.m[0][1] << endl;`
	`64`	`+}`

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