【luogu P1558 色板游戏】 题解

题目链接：https://www.luogu.org/problemnew/show/P1558

我知道三十棵线段树很暴力，可是我们可以状压啊。

颜色最多30，不会爆int

另外 吐槽评测机

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
const int maxn = 100010;
int n, k, c, q;
class Segment_Tree{
    public:
        #define lson l, mid, rt<<1
        #define rson mid+1, r, rt<<1|1
        int tree[maxn<<2], lazy[maxn<<2];
        void build(int l, int r, int rt)
        {
            if(l == r)
            {
                tree[rt] = 1<<1;
                return;
            }
            int mid = (l + r) >> 1;
            build(lson);
            build(rson);
            PushUP(rt);
        }
        void update(int left, int right, int add, int l, int r, int rt)
        {
            if(l >= left && r <= right)
            {
                lazy[rt] = add;
                tree[rt] = (1 << add);
                return;
            }
            int mid = (l + r) >> 1;
            PushDOWN(l, r, rt);
            if(left <= mid) update(left, right, add, lson);
            if(right > mid) update(left, right, add, rson);
            PushUP(rt);
        }
        int query(int left, int right, int l, int r, int rt)
        {
            int res = 0;
            if(l >= left && r <= right)
            {
                return tree[rt];
            }
            int mid = (l + r) >> 1;
            PushDOWN(l, r, rt);
            if(left <= mid) res |= query(left, right, lson);
            if(right > mid) res |= query(left, right, rson);
            return res;
        }
    private:
        void PushUP(int rt)
        {
            tree[rt] = tree[rt<<1] | tree[rt<<1|1];
        }
        void PushDOWN(int l, int r, int rt)
        {
            if(lazy[rt])
            {
                tree[rt<<1] = (1 << lazy[rt]);
                tree[rt<<1|1] = (1 << lazy[rt]);
                lazy[rt<<1] = lazy[rt];
                lazy[rt<<1|1] = lazy[rt];
                lazy[rt] = 0;
            }
        }
}T;
int main()
{
    scanf("%d%d%d",&n,&c,&q);
    T.build(1,n,1);
    for(int i = 1; i <= q; i++)
     {
     	char opt;
     	int x, y, k;
        cin>>opt;
        if(opt=='C')
          {
            scanf("%d%d%d",&x, &y, &k);
            if (x > y) swap(x, y);
            T.update(x, y, k, 1, n, 1);
        }
        else
          {
            scanf("%d%d",&x,&y);
            if (x > y) swap(x, y);
            int res = T.query(x,y,1,n,1), ans=0;
            for (int j = 1; j <= c; j++) if (res & (1 << j)) ans++;
            printf("%d\n",ans);
        }
    }
    return 0;
}