昨天学习了线段树的延迟标记；
发现自己还有区间合并没有学；
抓紧时间学习一下；
代码：
1 #include<cstdio> 2 #include<algorithm> 3 #define maxn 200005 4 using namespace std; 5 6 struct tree 7 { 8 int l,r,msum,lsum,rsum,flag; 9 tree *right,*left; 10 }tr[maxn]; 11 int nonocount; 12 13 void build(tree *root,int l,int r) 14 { 15 root->l=l,root->r=r,root->flag=-1; 16 root->msum=root->lsum=root->rsum=r-l+1; 17 if(l==r)return; 18 int mid=(l+r)>>1; 19 nonocount++; 20 root->left=tr+nonocount; 21 nonocount++; 22 root->right=tr+nonocount; 23 build(root->left,l,mid); 24 build(root->right,mid+1,r); 25 } 26 27 void pushdown(tree *root,int mid) 28 { 29 if(root->flag!=-1) 30 { 31 root->left->flag=root->right->flag=root->flag; 32 int x=root->flag?0:mid-(mid>>1); 33 root->left->lsum=root->left->msum=root->left->rsum=x; 34 int y=root->flag?0:(mid>>1); 35 root->right->lsum=root->right->msum=root->right->rsum=y; 36 root->flag=-1; 37 } 38 } 39 40 void pushup(tree *root,int mid) 41 { 42 root->lsum=root->left->lsum; 43 root->rsum=root->right->rsum; 44 if(root->lsum==mid-(mid>>1))root->lsum+=root->right->lsum; 45 if(root->rsum==(mid>>1))root->rsum+=root->left->rsum; 46 root->msum=max(root->right->lsum+root->left->rsum,max(root->left->msum,root->right->msum)); 47 } 48 49 void update(tree *root,int l,int r,int c) 50 { 51 int x=root->r-root->l+1; 52 if(l<=root->l&&root->r<=r) 53 { 54 root->msum=root->lsum=root->rsum=c?0:x; 55 root->flag=c; 56 return; 57 } 58 pushdown(root,x); 59 int mid=(root->l+root->r)>>1; 60 if(l<=mid)update(root->left,l,r,c); 61 if(r>mid) update(root->right,l,r,c); 62 pushup(root,x); 63 } 64 65 int query(tree *root,int w) 66 { 67 int x=root->r-root->l+1; 68 if(root->l==root->r)return root->l; 69 pushdown(root,x); 70 int mid=(root->l+root->r)>>1; 71 if(root->left->msum>=w)return query(root->left,w); 72 else if(root->left->rsum+root->right->lsum>=w)return mid-root->left->rsum+1; 73 return query(root->right,w); 74 } 75 int n,m,a,b,c; 76 int main() 77 { 78 scanf("%d%d",&n,&m); 79 build(tr,1,n); 80 while(m--) 81 { 82 scanf("%d",&a); 83 if(a==1) 84 { 85 scanf("%d",&b); 86 if(tr->msum<b)puts("0"); 87 else 88 { 89 int p=query(tr,b); 90 printf("%d ",p); 91 update(tr,p,p+b-1,1); 92 } 93 } 94 else 95 { 96 scanf("%d%d",&b,&c); 97 update(tr,b,b+c-1,0); 98 } 99 } 100 return 0; 101 }