HDU 3397 -- sequence operation (line segment tree, interval coloring + interval exclusive or + interval merging)

Sequence operation Time Limit: 10000/5000 MS (Java/others) memory limit: 32768/32768 K (Java/Others)
Total submission (s): 6270 accepted submission (s): 1862


Problem descriptionlxhgww 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]
Inputt (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.
Outputfor each output operation, output the result.
Sample Input

110 100 0 0 1 1 0 1 0 1 11 0 23 0 52 2 24 0 40 3 62 3 74 2 81 0 50 5 63 3 9

 
Sample output

5265

 

-----------------------Split line----------------

Question:

Five operations are available for a sequence of N numbers.

1: 0 a B overwrites the range [a, B] to 0

A B overwrites the range [a, B] to 1

A B: Change the range [a, B] 0 to 1, 1, and 0.

A B query the number of intervals [a, B] 1

A B The number of consecutive 1 rows in the query interval [a, B]

Ideas:

Push_up maintenance:

Left Continuous, right continuous, the total number of consecutive 0/1

Total number of 1

Push_down lazy flag:

Overwrite mark, exclusive or mark

When the information of a node is modified, push_up is required. For an exclusive or flag or overwrite mark, overwrite mark is preferred, and then an exclusive or flag is considered.

Push_down is required for Interval search

The details are important !!! Deepen understanding of push_up and push_down

#include<iostream>#include<cstdio>#include<cstring>#include<algorithm>const int maxn=100001;#define lson l,m,rt<<1#define rson m+1,r,rt<<1|1using namespace std;int lc[maxn<<2],rc[maxn<<2],mc[maxn<<2];int lc0[maxn<<2],rc0[maxn<<2],mc0[maxn<<2];int cov[maxn<<2],Xor[maxn<<2],sum[maxn<<2];void f_xor(int rt,int m){    if(cov[rt]!=-1) cov[rt]^=1;    else Xor[rt]^=1;    swap(lc[rt],lc0[rt]);    swap(rc[rt],rc0[rt]);    swap(mc[rt],mc0[rt]);    sum[rt]=m-sum[rt];}void f_cov(int rt,int m,int c){    cov[rt]=c;    Xor[rt]=0;    lc0[rt]=rc0[rt]=mc0[rt]=c ?0:m;    lc[rt]=rc[rt]=mc[rt]=sum[rt]=c ? m:0;}void push_down(int rt,int m){    if(cov[rt]!=-1) {        f_cov(rt<<1,m-(m>>1),cov[rt]);        f_cov(rt<<1|1,m>>1,cov[rt]);        cov[rt]=-1;        Xor[rt]=0;    }    if(Xor[rt]) {        f_xor(rt<<1,m-(m>>1));        f_xor(rt<<1|1,m>>1);        Xor[rt]=0;    }}void push_up(int rt,int m){    sum[rt]=sum[rt<<1]+sum[rt<<1|1];    lc[rt]=lc[rt<<1];    rc[rt]=rc[rt<<1|1];    if(lc[rt]==m-(m>>1))        lc[rt]+=lc[rt<<1|1];    if(rc[rt]==m>>1)        rc[rt]+=rc[rt<<1];    mc[rt]=max(rc[rt<<1]+lc[rt<<1|1],max(mc[rt<<1],mc[rt<<1|1]));    lc0[rt]=lc0[rt<<1];    rc0[rt]=rc0[rt<<1|1];    if(lc0[rt]==m-(m>>1))        lc0[rt]+=lc0[rt<<1|1];    if(rc0[rt]==m>>1)        rc0[rt]+=rc0[rt<<1];    mc0[rt]=max(lc0[rt<<1|1]+rc0[rt<<1],max(mc0[rt<<1],mc0[rt<<1|1]));}void build(int l,int r,int rt){    cov[rt]=-1;    Xor[rt]=0;    if(l==r) {        scanf("%d",&sum[rt]);        cov[rt]=lc[rt]=rc[rt]=mc[rt]=sum[rt];        lc0[rt]=rc0[rt]=mc0[rt]= 1-sum[rt];        return ;    }    int m=(l+r)>>1;    build(lson);    build(rson);    push_up(rt,r-l+1);}void update(int op,int L,int R,int l,int r,int rt){    if(L<=l&&r<=R) {        if(op==0)            f_cov(rt,r-l+1,0);        if(op==1)            f_cov(rt,r-l+1,1);        if(op==2)            f_xor(rt,r-l+1);        return ;    }    push_down(rt,r-l+1);    int m=(l+r)>>1;    if(L<=m) update(op,L,R,lson);    if(m<R) update(op,L,R,rson);    push_up(rt,r-l+1);}int query_sum(int L,int R,int l,int r,int rt){    if(L<=l&&r<=R) {        return sum[rt];    }    push_down(rt,r-l+1);    int m=(l+r)>>1;    int ans=0;    if(L<=m)        ans+=query_sum(L,R,lson);    if(m<R)        ans+=query_sum(L,R,rson);    return ans;}int query_len(int L,int R,int l,int r,int rt){    if(L<=l&&r<=R) {        return mc[rt];    }    push_down(rt,r-l+1);    int m=(l+r)>>1;    int ans=0;    if(L<=m)        ans=max(ans,query_len(L,R,lson));    if(m<R)        ans=max(ans,query_len(L,R,rson));    return max(ans,min(m-L+1,rc[rt<<1])+min(R-m,lc[rt<<1|1]));}int main(){    int T,n,m;    cin>>T;    while(T--) {        scanf("%d %d",&n,&m);        build(0,n-1,1);        int op,l,r;        while(m--) {            scanf("%d %d %d",&op,&l,&r);            if(op<=2)                update(op,l,r,0,n-1,1);            if(op==3)                printf("%d\n",query_sum(l,r,0,n-1,1));            if(op==4)                printf("%d\n",query_len(l,r,0,n-1,1));        }    }    return 0;}

HDU 3397 -- sequence operation (line segment tree, interval coloring + interval exclusive or + interval merging)