poj2777线段树+涂色问题

#include<cstdio>
#include<cstring>
using namespace std;

const int MaxN = 100010;
struct tree{
int l , r , col ;
bool cover;//1表示区间都是一种颜色
}tree[MaxN << 2];
int sum;//位运算有几个1就是几种颜色
void PushUp(int rt){
tree[rt].col = tree[rt << 1].col | tree[rt << 1 | 1].col;
}

void buildT(int l , int r , int rt)
{
tree[rt].l = l;
tree[rt].r = r;
tree[rt].col = 1;//一开始都是一种颜色
tree[rt].cover = 1;//每个叶子节点的颜色都相同
if(tree[rt].l == tree[rt].r) return;
int m = (l + r ) >> 1;
buildT(l , m , rt << 1);
buildT(m + 1 , r , rt << 1 | 1);
}

void PushDown(int rt)//更新叶子节点
{
tree[rt << 1].col = tree[rt].col;
tree[rt << 1].cover = 1;
tree[rt << 1 | 1].col = tree[rt].col;
tree[rt << 1 | 1].cover = 1;
tree[rt].cover = 0;
}

void update(int val , int l , int r, int rt)//更新操作
{
if(l <= tree[rt].l && r >= tree[rt].r){
tree[rt].col = val;
tree[rt].cover = 1;
return ;
}
if(tree[rt].col == val)
return ;
if(tree[rt].cover) PushDown(rt);
int m = (tree[rt].l + tree[rt].r) >> 1;
if(r <= m) update(val , l , r , rt << 1);
else if(l > m) update(val , l , r ,rt << 1 | 1);
else{
update(val , l , m , rt << 1 );
update(val ,m + 1 , r , rt << 1 | 1);
}
PushUp(rt);//更新爸爸节点
}

void query(int l , int r , int rt)
{
if(l <= tree[rt].l && r >= tree[rt].r){
sum |= tree[rt].col;
return;
}
if(tree[rt].cover){
sum |= tree[rt].col;
return;
}
int mid = (tree[rt].l + tree[rt].r) >> 1;
if(r <= mid) query(l , r , rt << 1);
else if(l > mid) query(l , r , rt << 1 | 1);
else{
query(l , mid , rt << 1);
query(mid + 1, r ,rt << 1 | 1);
}
}

int solve()//计算有几种颜色
{
int ans = 0;
while(sum){
if(sum & 1) ans++;
sum >>= 1;
}
return ans;
}
void swap(int &a,int &b)
{
int tmp = a; a = b; b = tmp;
}
int main(){

//freopen("input.txt","r",stdin);

int n,t,m;
while(~scanf("%d%d%d",&n,&t,&m)){
buildT(1,n,1);
char op[3];
int a,b,c;
while(m--){
scanf("%s",op);
if(op[0]=='C'){
scanf("%d%d%d",&a,&b,&c);
if(a>b)
swap(a,b);
update(1<<(c-1),a,b,1); // int型的右起第c位变为1，即2的c-1次方。
}else{
scanf("%d%d",&a,&b);
if(a>b)
swap(a,b);
sum=0;
query(a,b,1);
printf("%d\n",solve());
}
}
}
return 0;
}