hdu3397 Sequence operation 线段树

hdu3397 Sequence operation

 #include <bits/stdc++.h>
 using namespace std;
 const int maxn = 1e6+;
 struct node {
     /// l,r表示当前结点区间范围[l,r]
     int l, r;
     /// val=0时为全0标志，表示区间[l,r]的值全为0
     /// val=1时为全1标志，表示区间[l,r]的值全为1
     /// val=-1时则代表无操作
     /// xor为异或标志，表示区间[l,r]的值取异或操作
     int val, Xor;
     /// lmax_0表示区间[l,r]从左往右开始连续0的个数
     /// rmax_0表示区间[l,r]从右往左开始连续0的个数
     /// max_0表示当前区间最大连续0的个数
     int lmax_0, rmax_0, max_0, sum_0;
     int lmax_1, rmax_1, max_1, sum_1;
     /// 得到当前区间长度
     int len() { return r-l+; }

     /// 更新操作，val_代表01操作，xor_代表异或操作
     void change(int val_, int Xor_) {
         /// [l,r]全置为0
         if (val_ == ) {
             lmax_0 = rmax_0 = max_0 = sum_0 = len();
             lmax_1 = rmax_1 = max_1 = sum_1 = ;
             val = , Xor = ;
         }
         /// [l,r]全置为1
         else if (val_ == ) {
             lmax_0 = rmax_0 = max_0 = sum_0 = ;
             lmax_1 = rmax_1 = max_1 = sum_1 = len();
             val = , Xor = ;
         }
         /// [l,r]全异或
         if (Xor_ == ) {
             swap(lmax_0,lmax_1); swap(rmax_0,rmax_1);
             swap(max_0,max_1); swap(sum_0,sum_1);
             Xor ^= ;
         }
     }
 }tree[maxn*];
 int a[maxn];
 void pushup(node &fa, node &ls, node &rs) {
     /// 父节点的左边最长0串=左子树的左边最长0串
     fa.lmax_0 = ls.lmax_0, fa.rmax_0 = rs.rmax_0;
     fa.lmax_1 = ls.lmax_1, fa.rmax_1 = rs.rmax_1;
     /// 父节点0的数量=左子树0的数量+右子树0的数量
     fa.sum_0 = ls.sum_0+rs.sum_0;
     fa.sum_1 = ls.sum_1+rs.sum_1;
     /// 父节点最大连续0串等于左右子树里面中最大连续0串的最大值
     /// 或者是左子树从右开始的0串+右子树从左开始的0串之和
     fa.max_0 = max(max(ls.max_0,rs.max_0), ls.rmax_0+rs.lmax_0);
     fa.max_1 = max(max(ls.max_1,rs.max_1), ls.rmax_1+rs.lmax_1);

     /// 如果左子树整串都为0串
     if (ls.len() == ls.lmax_0) fa.lmax_0 += rs.lmax_0;
     if (ls.len() == ls.lmax_1) fa.lmax_1 += rs.lmax_1;
     if (rs.len() == rs.rmax_0) fa.rmax_0 += ls.rmax_0;
     if (rs.len() == rs.rmax_1) fa.rmax_1 += ls.rmax_1;
 }
 void pushdown(int rt) {
     if (tree[rt].val != - || tree[rt].Xor) {
         tree[rt*].change(tree[rt].val,tree[rt].Xor);
         tree[rt*+].change(tree[rt].val,tree[rt].Xor);
         tree[rt].val = -, tree[rt].Xor = ;
     }
 }
 void build(int rt, int l, int r) {
     /// 结点初始化
     tree[rt].l = l, tree[rt].r = r;
     tree[rt].lmax_0 = tree[rt].rmax_0 = ;
     tree[rt].lmax_1 = tree[rt].rmax_1 = ;
     tree[rt].max_0 = tree[rt].max_1 = ;
     tree[rt].sum_0 = tree[rt].sum_1 = ;
     tree[rt].Xor = , tree[rt].val = -;
     /// 如果是叶子结点
     if (l == r) {
         tree[rt].change(a[l],);
         return;
     }
     int mid = (l+r)/;
     build(rt*,l,mid);
     build(rt*+,mid+,r);
     pushup(tree[rt],tree[rt*],tree[rt*+]);
 }
 void update(int rt, int l, int r, int op) {
     int L = tree[rt].l, R = tree[rt].r;
     if (l <= L && R <= r) {
         /// 根据op执行不同操作
         if (op ==  || op == ) tree[rt].change(op,);
         else if (op == ) tree[rt].change(-,);
         return;
     }
     pushdown(rt);
     int mid = (L+R)/;
     if (mid >= l) update(rt*,l,r,op);
     if (mid < r) update(rt*+,l,r,op);
     pushup(tree[rt],tree[rt*],tree[rt*+]);
 }
 int query(int rt, int l, int r, int op) {
     int L = tree[rt].l, R = tree[rt].r;
     if (l <= L && R <= r) {
         if (op == ) return tree[rt].sum_1;
         else if (op == ) return tree[rt].max_1;
     }
     int mid = (L+R)/;
     pushdown(rt);
     if (r <= mid) return query(rt*,l,r,op);
     else if (l > mid) return query(rt*+,l,r,op);
     else {
         int max1 = query(rt*,l,r,op);
         int max2 = query(rt*+,l,r,op);
         if (op == ) return max1+max2;
         int max3 = min(tree[rt*].r-l+,tree[rt*].rmax_1)+min(r-tree[rt*+].l+,tree[rt*+].lmax_1);
         return max(max(max1,max2),max3);
     }
 }
 int main() {
     int t; scanf("%d",&t);
     while (t--) {
         int n, m; scanf("%d%d",&n,&m);
         for (int i = ; i < n; ++i)
             scanf("%d",&a[i]);
         build(,,n-);
         while (m--) {
             int op, a, b;
             scanf("%d%d%d",&op,&a,&b);
             if (op ==  || op ==  || op == ) update(,a,b,op);
             else printf("%d\n",query(,a,b,op));
         }
     }
     return ;
 }