类似(ST表)的思想,倍增(log(n))地合并
你是我家的吗?不是就来呀啦啦啦。还有要来的吗?没了!那有多少个家就映射多少答案呀
倍增原来这么好玩
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#define R(a,b,c) for(register int a = (b); a <= (c); ++a)
#define nR(a,b,c) for(register int a = (b); a >= (c); --a)
#define Fill(a,b) memset(a, b, sizeof(a))
#define Swap(a,b) ((a) ^= (b) ^= (a) ^= (b))
#define ON_DEBUGG
#ifdef ON_DEBUGG
#define D_e_Line printf("
-----------
")
#define D_e(x) std::cout << (#x) << " : " <<x << "
"
#define FileOpen() freopen("in.txt", "r", stdin)
#define FileSave() freopen("out.txt", "w", stdout)
#define Pause() system("pause")
#include <ctime>
#define TIME() fprintf(stderr, "
TIME : %.3lfms
", clock() * 1000.0 / CLOCKS_PER_SEC)
#else
#define D_e_Line ;
#define D_e(x) ;
#define FileOpen() ;
#define FilSave ;
#define Pause() ;
#define TIME() ;
#endif
struct ios {
template<typename ATP> ios& operator >> (ATP &x) {
x = 0; int f = 1; char c;
for(c = getchar(); c < '0' || c > '9'; c = getchar()) if(c == '-') f = -1;
while(c >= '0' && c <= '9') x = x * 10 + (c ^ '0'), c = getchar();
x *= f;
return *this;
}
}io;
using namespace std;
template<typename ATP> inline ATP Min(ATP a, ATP b) {
return a < b ? a : b;
}
template<typename ATP> inline ATP Max(ATP a, ATP b) {
return a > b ? a : b;
}
const int N = 1e5 + 7;
const int mod = 1e9 + 7;
int fa[N][18];
inline int Find(int x, int t) {
return x == fa[x][t] ? x : fa[x][t] = Find(fa[x][t], t);
}
inline void Merge(int x, int y, int t) {
int p = Find(x, t), q = Find(y, t);
if(p != q){
fa[p][t] = q;
if(t){
Merge(x, y, t - 1), Merge(x + (1 << (t - 1)), y + (1 << (t - 1)), t - 1);
}
}
}
inline long long Pow(long long a, long long b) {
long long s = 1;
while(b){
if(b & 1) s = s * a % mod;
a = a * a % mod, b >>= 1;
}
return s;
}
int lg[N];
int main() {
int n, m;
io >> n >> m;
if(n == 1){
printf("10");
return 0;
}
R(i,2,n) lg[i] = lg[i >> 1] + 1;
R(i,1,n){
R(j,0,17)
fa[i][j] = i;
}
R(i,1,m){
int l1, r1, l2, r2;
io >> l1 >> r1 >> l2 >> r2;
int t = lg[r1 - l1 + 1];
Merge(l1, l2, t), Merge(r1 - (1 << t) + 1, r2 - (1 << t) + 1, t);
}
int ans = 0;
R(i,1,n){
ans += (Find(i, 0) == i);
}
printf("%lld
", (9 * Pow(10, ans - 1) + mod) % mod);
return 0;
}