HDU - 3397 Sequence operation 線段樹 區間合併
阿新 • • 發佈：2018-11-02
lxhgww got a sequence contains n characters which are all '0's or '1's.
We have five operations here:
Change operations:
0 a b change all characters into '0's in [a , b]
1 a b change all characters into '1's in [a , b]
2 a b change all '0's into '1's and change all '1's into '0's in [a, b]
Output operations:
3 a b output the number of '1's in [a, b]
4 a b output the length of the longest continuous '1' string in [a , b]
Input
T(T<=10) in the first line is the case number.
Each case has two integers in the first line: n and m (1 <= n , m <= 100000).
The next line contains n characters, '0' or '1' separated by spaces.
Then m lines are the operations:
op a b: 0 <= op <= 4 , 0 <= a <= b < n.
Output
For each output operation , output the result.
Sample Input
1
10 10
0 0 0 1 1 0 1 0 1 1
1 0 2
3 0 5
2 2 2
4 0 4
0 3 6
2 3 7
4 2 8
1 0 5
0 5 6
3 3 9Sample Output
5
2
6
5題解：小細節害死人，區間合併，分別記錄 連續0的和連續1 的 改變的之後交換就好，另外就是，在全部變成0或1後 異或也就沒用了，清0就好
#include<iostream> #include<cstdio> using namespace std; const int N=1e5+10; struct node { int l,r,len; int l0,r0,max0; int l1,r1,max1; int sum; int laz; int fg; }tree[N<<2]; int n,q,x; void pushup(int cur) { tree[cur].l0=tree[cur<<1].l0; if(tree[cur<<1].l0==tree[cur<<1].len) tree[cur].l0+=tree[cur<<1|1].l0; tree[cur].r0=tree[cur<<1|1].r0; if(tree[cur<<1|1].r0==tree[cur<<1|1].len) tree[cur].r0+=tree[cur<<1].r0; tree[cur].max0=max(tree[cur<<1].max0,tree[cur<<1|1].max0); tree[cur].max0=max(tree[cur].max0,tree[cur<<1].r0+tree[cur<<1|1].l0); tree[cur].l1=tree[cur<<1].l1; if(tree[cur<<1].l1==tree[cur<<1].len) tree[cur].l1+=tree[cur<<1|1].l1; tree[cur].r1=tree[cur<<1|1].r1; if(tree[cur<<1|1].r1==tree[cur<<1|1].len) tree[cur].r1+=tree[cur<<1].r1; tree[cur].max1=max(tree[cur<<1].max1,tree[cur<<1|1].max1); tree[cur].max1=max(tree[cur].max1,tree[cur<<1].r1+tree[cur<<1|1].l1); tree[cur].sum=tree[cur<<1].sum+tree[cur<<1|1].sum; } void build(int l,int r,int cur) { tree[cur].laz=0; tree[cur].l=l; tree[cur].r=r; tree[cur].fg=-1; tree[cur].len=r-l+1; if(l==r) { scanf("%d",&x); tree[cur].l1=tree[cur].r1=tree[cur].max1=(x==1); tree[cur].l0=tree[cur].r0=tree[cur].max0=(x==0); tree[cur].sum=x; return; } int mid=(r+l)>>1; build(l,mid,cur<<1); build(mid+1,r,cur<<1|1); pushup(cur); } void change(int cur) { swap(tree[cur].l0,tree[cur].l1); swap(tree[cur].r0,tree[cur].r1); swap(tree[cur].max0,tree[cur].max1); tree[cur].sum=tree[cur].len-tree[cur].sum; } void pushdown(int cur) { if(tree[cur].len==1) return; if(tree[cur].fg!=-1) { tree[cur<<1].fg=tree[cur<<1|1].fg=tree[cur].fg; if(tree[cur].fg==1) { tree[cur<<1].l0=tree[cur<<1].r0=tree[cur<<1].max0=0; tree[cur<<1].l1=tree[cur<<1].r1=tree[cur<<1].max1=tree[cur<<1].len; tree[cur<<1|1].l0=tree[cur<<1|1].r0=tree[cur<<1|1].max0=0; tree[cur<<1|1].l1=tree[cur<<1|1].r1=tree[cur<<1|1].max1=tree[cur<<1|1].len; tree[cur<<1].sum=tree[cur<<1].len; tree[cur<<1|1].sum=tree[cur<<1|1].len; } else { tree[cur<<1].l0=tree[cur<<1].r0=tree[cur<<1].max0=tree[cur<<1].len; tree[cur<<1].l1=tree[cur<<1].r1=tree[cur<<1].max1=0; tree[cur<<1|1].l0=tree[cur<<1|1].r0=tree[cur<<1|1].max0=tree[cur<<1|1].len; tree[cur<<1|1].l1=tree[cur<<1|1].r1=tree[cur<<1|1].max1=0; tree[cur<<1].sum=0; tree[cur<<1|1].sum=0; } tree[cur].fg=-1; tree[cur<<1].laz=tree[cur<<1|1].laz=0; } if(tree[cur].laz) { tree[cur<<1].laz^=1; tree[cur<<1|1].laz^=1; change(cur<<1); change(cur<<1|1); tree[cur].laz=0; } } void update(int pl,int pr,int cur,int fg) { if(pl<=tree[cur].l&&tree[cur].r<=pr) { if(fg==0) { tree[cur].fg=0; tree[cur].l0=tree[cur].r0=tree[cur].max0=tree[cur].len; tree[cur].l1=tree[cur].r1=tree[cur].max1=0; tree[cur].sum=0; tree[cur].laz=0; } if(fg==1) { tree[cur].fg=1; tree[cur].l0=tree[cur].r0=tree[cur].max0=0; tree[cur].l1=tree[cur].r1=tree[cur].max1=tree[cur].len; tree[cur].sum=tree[cur].len; tree[cur].laz=0; } if(fg==2) { tree[cur].laz^=1; change(cur); } return; } pushdown(cur); if(pl<=tree[cur<<1].r) update(pl,pr,cur<<1,fg); if(pr>=tree[cur<<1|1].l) update(pl,pr,cur<<1|1,fg); pushup(cur); } int query(int pl,int pr,int cur) { if(pl<=tree[cur].l&&tree[cur].r<=pr) { return tree[cur].max1; } pushdown(cur); if(pr<=tree[cur<<1].r) return query(pl,pr,cur<<1); else if(pl>=tree[cur<<1|1].l) return query(pl,pr,cur<<1|1); else { int res=min(pr,tree[cur<<1|1].l1+tree[cur<<1|1].l-1)-max(pl,tree[cur<<1].r-tree[cur<<1].r1+1)+1; res=max(res,query(pl,pr,cur<<1)); res=max(res,query(pl,pr,cur<<1|1)); return res; } } int query_(int pl,int pr,int cur) { // printf("%d-%d %d %d-%d\n",tree[cur].l,tree[cur].r,tree[cur].sum,pl,pr); if(pl<=tree[cur].l && tree[cur].r<=pr) { return tree[cur].sum; } int res=0; pushdown(cur); if(pl<=tree[cur<<1].r) res+=query_(pl,pr,cur<<1); if(pr>=tree[cur<<1|1].l) res+=query_(pl,pr,cur<<1|1); return res; } int main() { int op,l,r; int T; scanf("%d",&T); while(T--) { scanf("%d%d",&n,&q); build(1,n,1); while(q--) { scanf("%d%d%d",&op,&l,&r); l++,r++; if(op==0||op==1||op==2) update(l,r,1,op); else if(op==3) printf("%d\n",query_(l,r,1)); else printf("%d\n",query(l,r,1)); } } return 0; }