题目链接：http://poj.org/problem?id=2777
给你一个长为L想线段，向上面染色，颜色不超过３０种，一共有Ｏ次操作，操作有两种：
C a b c 在[a,b]上染上c颜色
P a b 查询[a,b]上所有颜色数。
思路：线段树维护每个线段上颜色种类，用位来存颜色。好题。
1 /* 2 ━━━━━┒ギリギリ♂ eye！ 3 ┓┏┓┏┓┃キリキリ♂ mind！ 4 ┛┗┛┗┛┃＼○／ 5 ┓┏┓┏┓┃ / 6 ┛┗┛┗┛┃ノ) 7 ┓┏┓┏┓┃ 8 ┛┗┛┗┛┃ 9 ┓┏┓┏┓┃ 10 ┛┗┛┗┛┃ 11 ┓┏┓┏┓┃ 12 ┛┗┛┗┛┃ 13 ┓┏┓┏┓┃ 14 ┃┃┃┃┃┃ 15 ┻┻┻┻┻┻ 16 */ 17 #include <algorithm> 18 #include <iostream> 19 #include <iomanip> 20 #include <cstring> 21 #include <climits> 22 #include <complex> 23 #include <fstream> 24 #include <cassert> 25 #include <cstdio> 26 #include <bitset> 27 #include <vector> 28 #include <deque> 29 #include <queue> 30 #include <stack> 31 #include <ctime> 32 #include <set> 33 #include <map> 34 #include <cmath> 35 using namespace std; 36 #define fr first 37 #define sc second 38 #define cl clear 39 #define BUG puts("here!!!") 40 #define W(a) while(a--) 41 #define pb(a) push_back(a) 42 #define Rint(a) scanf("%d", &(a)) 43 #define Rll(a) scanf("%I64d", &a) 44 #define Rs(a) scanf("%s", a) 45 #define Cin(a) cin >> a 46 #define FRead() freopen("in", "r", stdin) 47 #define FWrite() freopen("out", "w", stdout) 48 #define Rep(i, len) for(int i = 0; i < (len); i++) 49 #define For(i, a, len) for(int i = (a); i < (len); i++) 50 #define Cls(a) memset((a), 0, sizeof(a)) 51 #define Clr(a, x) memset((a), (x), sizeof(a)) 52 #define Full(a) memset((a), 0x7f, sizeof(a)) 53 #define lrt rt << 1 54 #define rrt rt << 1 | 1 55 #define pi 3.14159265359 56 #define RT return 57 #define lowbit(x) x & (-x) 58 #define onenum(x) __builtin_popcount(x) 59 typedef long long LL; 60 typedef long double LD; 61 typedef unsigned long long Uint; 62 typedef pair<int, int> pii; 63 typedef pair<LL, LL> pLL; 64 typedef pair<string, LL> psi; 65 typedef map<string, LL> msi; 66 typedef vector<LL> vi; 67 typedef vector<LL> vl; 68 typedef vector<vl> vvl; 69 typedef vector<bool> vb; 70 71 #define lson l, m, rt << 1 72 #define rson m + 1, r, rt << 1 | 1 73 const int maxn = 100010; 74 int sum[maxn<<2]; 75 int add[maxn<<2]; 76 int L, T, O; 77 78 void pushUP(int rt) { 79 sum[rt] = sum[lrt] | sum[rrt]; 80 } 81 82 void pushDOWN(int rt) { 83 if(add[rt] != -1) { 84 sum[lrt] = sum[rrt] = (1 << add[rt]); 85 add[lrt] = add[rrt] = add[rt]; 86 add[rt] = -1; 87 } 88 } 89 90 void build(int l, int r, int rt) { 91 sum[rt] = 1; add[rt] = 1; 92 if(l == r) return; 93 int m = (l + r) >> 1; 94 build(l, m, lrt); 95 build(m+1, r, rrt); 96 } 97 98 void update(int L, int R, int c, int l, int r, int rt) { 99 if(L <= l && r <= R) { 100 add[rt] = c; 101 sum[rt] = 1 << c; 102 return; 103 } 104 pushDOWN(rt); 105 int m = (l + r) >> 1; 106 if(L <= m) update(L, R, c, lson); 107 if(m < R) update(L, R, c, rson); 108 pushUP(rt); 109 } 110 111 int query(int L, int R, int l, int r, int rt) { 112 if(L <= l && r <= R) return sum[rt]; 113 pushDOWN(rt); 114 int m = (l + r) >> 1; 115 int ret = 0; 116 if(L <= m) ret |= query(L, R, lson); 117 if(m < R) ret |= query(L, R, rson); 118 return ret; 119 } 120 121 int main() { 122 // FRead(); 123 char cmd[2]; 124 int l, r, c; 125 while(~scanf("%d%d%d", &L, &T, &O)) { 126 build(1, L, 1); 127 W(O) { 128 Rs(cmd); 129 if(cmd[0] == 'C') { 130 scanf("%d%d%d",&l,&r,&c); 131 if(l > r) swap(l, r); 132 update(l, r, c, 1, L, 1); 133 } 134 else { 135 scanf("%d%d",&l,&r); 136 if(l > r) swap(l, r); 137 int p = query(l, r, 1, L, 1); 138 int ret = 0; 139 while(p) { 140 if(p & 1) ret++; 141 p >>= 1; 142 } 143 printf("%d ", ret); 144 } 145 } 146 } 147 RT 0; 148 }