POJ 3667

 1 #include <cstdio>
 2 #include <iostream>
 3 using namespace std;
 4 const int MAXN=50001<<2;
 5 #define chl l,mid,rt*2
 6 #define chr mid+1,r,rt*2+1
 7 int msum[MAXN],lsum[MAXN],rsum[MAXN],la[MAXN];
 8 void pushup(int l,int r,int rt){
 9     int mid=(l+r)/2;
10     lsum[rt]=lsum[rt*2]==mid-l+1?mid-l+1+lsum[rt*2+1]:lsum[rt*2];
11     rsum[rt]=rsum[rt*2+1]==r-mid?r-mid+rsum[rt*2]:rsum[rt*2+1];
12     msum[rt]=max(max(msum[rt*2],msum[rt*2+1]),lsum[rt*2+1]+rsum[rt*2]);
13 }
14 void pushdown(int l,int r,int rt){
15     if(la[rt]!=-1){
16         int mid=(l+r)/2;
17         la[rt*2]=la[rt*2+1]=la[rt];
18         msum[rt*2]=lsum[rt*2]=rsum[rt*2]=la[rt]*(mid-l+1);
19         msum[rt*2+1]=lsum[rt*2+1]=rsum[rt*2+1]=la[rt]*(r-mid);
20         la[rt]=-1;
21     }
22 }
23 void build(int l,int r,int rt){
24     msum[rt]=lsum[rt]=rsum[rt]=r-l+1;
25     la[rt]=-1;
26     if(l==r)return ;
27     int mid=(l+r)/2;
28     build(chl);
29     build(chr);
30 }
31 void update(int x,int y,int c,int l,int r,int rt){
32     if(x<=l&&y>=r){
33         msum[rt]=lsum[rt]=rsum[rt]=c*(r-l+1);
34         la[rt]=c;
35         return;
36     }
37     pushdown(l,r,rt);
38     int mid=(l+r)/2;
39     if(x<=mid)update(x,y,c,chl);
40     if(y>mid)update(x,y,c,chr);
41     pushup(l,r,rt);
42 }
43 int query(int c,int l,int r,int rt){
44     if(l==r)return l;
45     pushdown(l,r,rt);
46     int mid((l+r)/2);
47     if(msum[rt*2]>=c)return query(c,chl);
48     else if(rsum[rt*2]+lsum[rt*2+1]>=c)return mid-rsum[rt*2]+1;
49     else query(c,chr);
50 }
51 int main(){
52     //freopen("test.txt","r",stdin);
53     int n,m,sw,a,b;
54     scanf("%d%d",&n,&m);
55     build(1,n,1);
56     while(m--){
57         scanf("%d",&sw);
58         if(sw==1){
59             scanf("%d",&a);
60             if(msum[1]<a){printf("0\n");continue;}
61             int q=query(a,1,n,1);
62             printf("%d\n",q);
63             update(q,q+a-1,0,1,n,1);
64         }
65         else {
66             scanf("%d%d",&a,&b);
67             update(a,a+b-1,1,1,n,1);
68         }
69     }
70     return 0;
71 }