HDU 3397 线段树区间修改

Sequence operation

Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 8308    Accepted Submission(s): 2507

Problem Description

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 9

 

Sample Output

5
2
6
5

 

Author

lxhgww&&shǎ崽

及其恶心的一道题目，要维护许多变量= =

由于mx1函数写错找bug找了半天，最后发现自己的思路错了诶，可算A了。

中间维护的变量: 1的个数，0的个数，以第一个开始的最长连续0，以第一个开始的最长连续1，以最后一个开始的最长连续0，以最后一个开始的最长连续1，

区间最长连续1，区间最长连续0，可能有一些变量是互补的我写的有点多余不过感觉很方便把看起来，另外注意当操作为0/1时可以覆盖之前所有的标记。

我用0，1,2表示三种标记全0全1和翻转。len储存区间信息 一维表示'0'/'1'   二维表示 head，tail，max_continue_1  三维表示区间对应的结点值。

 #include<bits/stdc++.h>
 using namespace std;
 #define MAXN ((100000<<2)+15)
 int g[][]={,,,,,,,,-};
 struct SegmentTree
 {
     #define M ((L+R)>>1)
     #define lc (id<<1)
     #define rc (id<<1|1)
     int num[MAXN][],X;
     int len[][][MAXN];
     short int laz[MAXN];
     void show(int L,int R,int id)
     {
         if(L==R) {cout<<num[id][]<<" ";return;}
         push_down(L,R,id);
         show(L,M,lc);
         show(M+,R,rc);
         push_up(L,R,id);
     }
     void init()
     {
         memset(num,,sizeof(num));
         memset(laz,-,sizeof(laz));
         memset(len,,sizeof(len));
     }
     void push_up(int L,int R,int id)
     {
        num[id][]=num[lc][]+num[rc][];
        num[id][]=num[lc][]+num[rc][];
        for(int i=;i<=;++i){
         len[i][][id]=len[i][][lc];
         len[i][][id]=len[i][][rc];
         len[i][][id]=max(max(len[i][][lc],len[i][][rc]),len[i][][lc]+len[i][][rc]);
         if(!num[lc][i^]) len[i][][id]=max(len[i][][id],len[i][][lc]+len[i][][rc]);
         if(!num[rc][i^]) len[i][][id]=max(len[i][][id],len[i][][rc]+len[i][][lc]);
        }
     }
     void push_down(int L,int R,int id)
     {
         if(laz[id]==-) return;
           laz[lc]=laz[lc]==-?laz[id]:g[laz[id]][laz[lc]];
           laz[rc]=laz[rc]==-?laz[id]:g[laz[id]][laz[rc]];
         if(laz[id]<){
             num[lc][laz[id]^]=num[rc][laz[id]^]=;
             num[lc][laz[id]]=M-L+;
             num[rc][laz[id]]=R-M;
             len[laz[id]^][][lc]=len[laz[id]^][][lc]=len[laz[id]^][][lc]=;
             len[laz[id]^][][rc]=len[laz[id]^][][rc]=len[laz[id]^][][rc]=;
             len[laz[id]][][lc]=len[laz[id]][][lc]=len[laz[id]][][lc]=M-L+;
             len[laz[id]][][rc]=len[laz[id]][][rc]=len[laz[id]][][rc]=R-M;
         }
         else {
                 swap(num[lc][],num[lc][]);
                 swap(num[rc][],num[rc][]);
                 swap(len[][][lc],len[][][lc]); swap(len[][][lc],len[][][lc]); swap(len[][][lc],len[][][lc]);
                 swap(len[][][rc],len[][][rc]); swap(len[][][rc],len[][][rc]); swap(len[][][rc],len[][][rc]);
         }
           laz[id]=-;
     }
     void build(int L,int R,int id)
     {
         if(L==R)
         {
             scanf("%d",&X);num[id][X]++;
             len[X][][id]=len[X][][id]=len[X][][id]=;
             return;
         }
         build(L,M,lc);
         build(M+,R,rc);
         push_up(L,R,id);
     }
     void change(int L,int R,int id,int l,int r,int x)
     {
         if(L>=l&&R<=r){
             num[id][x^]=;
             num[id][x]=R-L+;
             len[x][][id]=len[x][][id]=len[x][][id]=R-L+;
             len[x^][][id]=len[x^][][id]=len[x^][][id]=;
             laz[id]=laz[id]==-?x:g[x][laz[id]];
             return;
         }
         push_down(L,R,id);
         if(l<=M) change(L,M,lc,l,r,x);
         if(r>M) change(M+,R,rc,l,r,x);
         push_up(L,R,id);
     }
     void swp(int L,int R,int id,int l,int r)
     {
         if(L>=l&&R<=r){
             swap(num[id][],num[id][]);
             laz[id]=laz[id]==-?:g[][laz[id]];
             swap(len[][][id],len[][][id]);
             swap(len[][][id],len[][][id]);
             swap(len[][][id],len[][][id]);
             return;
         }
         push_down(L,R,id);
         if(l<=M) swp(L,M,lc,l,r);
         if(r>M)  swp(M+,R,rc,l,r);
         push_up(L,R,id);
     }
     int num1(int L,int R,int id,int l,int r)
     {
         if(L>=l&&R<=r) return num[id][];
         push_down(L,R,id);
         int s=;
         if(l<=M) s+=num1(L,M,lc,l,r);
         if(r>M)  s+=num1(M+,R,rc,l,r);
         push_up(L,R,id);
         return s;
     }
     int mx1(int L,int R,int id,int l,int r)
     {
         if(L>=l&&R<=r) return len[][][id];
         push_down(L,R,id);
         int s=;
         if(r<=M) s=max(s, mx1(L,M,lc,l,r));
         else if(l>M) s=max(s,mx1(M+,R,rc,l,r));
         else {
                 int lm=len[][][lc],rm=len[][][rc];
         if(lm>M-l+) lm=M-l+;
         if(rm>r-M) rm=r-M;
                 s=max(s,max(max(mx1(L,M,lc,l,r),mx1(M+,R,rc,l,r)),lm+rm));
         }
         push_up(L,R,id);
         return s;
     }
 }seg;

 int main()
 {
     int t,n,m,i,j,k,opt,a,b;
     scanf("%d",&t);
     while(t--){
         scanf("%d%d",&n,&m);
         seg.init();
         seg.build(,n,);
     while(m--){
         scanf("%d%d%d",&opt,&a,&b);a++;b++;
         if(opt==)        seg.change(,n,,a,b,);
         else if(opt==)   seg.change(,n,,a,b,);
         else if(opt==)   seg.swp(,n,,a,b);
         else if(opt==)   printf("%d\n",seg.num1(,n,,a,b));
         else              printf("%d\n",seg.mx1(,n,,a,b));
     }
     }
     return ;
 }