【POJ 2777】 Count Color
【题目链接】
http://poj.org/problem?id=2777
【算法】
线段树
【代码】
#include <algorithm> #include <bitset> #include <cctype> #include <cerrno> #include <clocale> #include <cmath> #include <complex> #include <cstdio> #include <cstdlib> #include <cstring> #include <ctime> #include <deque> #include <exception> #include <fstream> #include <functional> #include <limits> #include <list> #include <map> #include <iomanip> #include <ios> #include <iosfwd> #include <iostream> #include <istream> #include <ostream> #include <queue> #include <set> #include <sstream> #include <stdexcept> #include <streambuf> #include <string> #include <utility> #include <vector> #include <cwchar> #include <cwctype> #include <stack> #include <limits.h> using namespace std; #define MAXN 100010 int N,T,Q,l,r,x,v; char op[5]; struct SegmentTree { struct Node { int l,r,s,tag; } Tree[MAXN<<2]; inline void build(int index,int l,int r) { Tree[index].l = l; Tree[index].r = r; Tree[index].s = 1; if (l == r) return; int mid = (l + r) >> 1; build(index<<1,l,mid); build(index<<1|1,mid+1,r); } inline void pushdown(int index) { if (Tree[index].tag) { Tree[index<<1].s = Tree[index<<1|1].s = 1 << (Tree[index].tag - 1); Tree[index<<1].tag = Tree[index<<1|1].tag = Tree[index].tag; Tree[index].tag = 0; } } inline void update(int index) { Tree[index].s = Tree[index<<1].s | Tree[index<<1|1].s; } inline void modify(int index,int l,int r,int val) { if (Tree[index].l == l && Tree[index].r == r) { Tree[index].s = 1 << (val - 1); Tree[index].tag = val; return; } pushdown(index); int mid = (Tree[index].l + Tree[index].r) >> 1; if (mid >= r) modify(index<<1,l,r,val); else if (mid + 1 <= l) modify(index<<1|1,l,r,val); else { modify(index<<1,l,mid,val); modify(index<<1|1,mid+1,r,val); } update(index); } inline int query(int index,int l,int r) { if (Tree[index].l == l && Tree[index].r == r) return Tree[index].s; pushdown(index); int mid = (Tree[index].l + Tree[index].r) >> 1; if (mid >= r) return query(index<<1,l,r); else if (mid + 1 <= l) return query(index<<1|1,l,r); else return query(index<<1,l,mid) | query(index<<1|1,mid+1,r); } } S; inline int calc(int x) { int ret = 0; while (x) { if (x & 1) ret++; x >>= 1; } return ret; } int main() { scanf("%d%d%d",&N,&T,&Q); S.build(1,1,N); while (Q--) { scanf("%s",&op); if (op[0] == 'C') { scanf("%d%d%d",&l,&r,&x); if (l > r) swap(l,r); S.modify(1,l,r,x); } else { scanf("%d%d",&l,&r); if (l > r) swap(l,r); v = S.query(1,l,r); printf("%d\n",calc(v)); } } return 0; }