4569: [Scoi2016]萌萌哒
分析:
每次给出的两个区间长度是一样的,对应位置的数字也是一样的,那么可以将两两对应的数字用并查集合并,设最后有$cnt$个不同的集合,答案就是$9\times 10 ^{cnt-1}$,第一个数不能是0。
暴力合并太慢了,考虑优化。对于一段区间,用倍增的思想分成log段,分别合并log段,最后的下放一下标记即可。类似线段树的懒标记。
代码:
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<iostream>
#include<cmath>
#include<cctype>
#include<set>
#include<queue>
#include<vector>
#include<map>
using namespace std;
typedef long long LL; inline int read() {
int x=,f=;char ch=getchar();for(;!isdigit(ch);ch=getchar())if(ch=='-')f=-;
for(;isdigit(ch);ch=getchar())x=x*+ch-'';return x*f;
} const int mod = 1e9 + , N = ;
int f[][N], Log[N]; int find(int x,int y) {
return f[y][x] == x ? x : f[y][x] = find(f[y][x], y);
}
void Union(int a,int b,int c) { // 合并两个段 [a,a+(1<<c)-1] 与 [b,b+(1<<c)-1]
if (find(a, c) != find(b, c)) f[c][f[c][a]] = f[c][b];
}
int main() {
int n = read(), m = read(), cnt = ;
for (int i = ; i <= n; ++i) Log[i] = Log[i >> ] + ;
for (int j = ; j <= Log[n]; ++j)
for (int i = ; i + ( << j) - <= n; ++i) f[j][i] = i;
for (int i = ; i <= m; ++i) {
int a = read(), b = read(), c = read(), d = read();
for (int j = Log[b - a + ]; ~j; --j)
if (a + ( << j) - <= b)
Union(a, c, j), a += ( << j), c += ( << j);
}
for (int j = Log[n]; j; --j) { // 下放标记
for (int i = ; i + ( << j) - <= n; ++i) {
Union(i, find(i, j), j - );
Union(i + ( << (j - )), find(i, j) + ( << (j - )), j - );
}
}
for (int i = ; i <= n; ++i) if (find(i, ) == i) cnt ++;
LL ans = ;
for (int i = ; i < cnt; ++i) ans = ans * % mod;
cout << ans;
return ;
}