1 #include<cstdio> 2 #include<cstring> 3 #include<algorithm> 4 #define MAXN 500010 5 using namespace std; 6 int x[MAXN]; 7 bool vis[MAXN]; 8 struct cmd 9 { 10 char s[6]; 11 int val; 12 }; 13 struct node 14 { 15 int left,right,val; 16 }; 17 node tree[MAXN<<2]; 18 cmd p[MAXN]; 19 void Build(int L,int R,int rt) 20 { 21 tree[rt].left=tree[rt].right=-1; 22 tree[rt].val=0; 23 if(L!=R) 24 { 25 int mid=(L+R)>>1; 26 Build(L,mid,rt<<1); 27 Build(mid+1,R,rt<<1|1); 28 } 29 } 30 inline int MIN(int a,int b) 31 { 32 if(!a&&!b) 33 return 0; 34 if(!a) 35 return b; 36 if(!b) 37 return a; 38 return a>b?b:a; 39 } 40 inline void PushUp(int L,int R,int rt) 41 { 42 if(tree[rt<<1].left>=0) 43 tree[rt].left=tree[rt<<1].left; 44 else 45 tree[rt].left=tree[rt<<1|1].left; 46 if(tree[rt<<1|1].right>=0) 47 tree[rt].right=tree[rt<<1|1].right; 48 else 49 tree[rt].right=tree[rt<<1].right; 50 tree[rt].val=MIN(tree[rt<<1].val,tree[rt<<1|1].val); 51 if(tree[rt].left>=0&&tree[rt].right>=0) 52 tree[rt].val=MIN(tree[rt].val,x[tree[rt].right]-x[tree[rt].left]); 53 if(tree[rt<<1].right>=0&&tree[rt<<1|1].left>=0) 54 tree[rt].val=MIN(tree[rt].val,x[tree[rt<<1|1].left]-x[tree[rt<<1].right]); 55 } 56 void Update(int pos,bool flag,int L,int R,int rt) 57 { 58 if(L==R) 59 { 60 if(flag) 61 tree[rt].left=tree[rt].right=L; 62 else 63 tree[rt].left=tree[rt].right=-1; 64 } 65 else 66 { 67 int mid=(L+R)>>1; 68 if(pos<=mid) 69 Update(pos,flag,L,mid,rt<<1); 70 else 71 Update(pos,flag,mid+1,R,rt<<1|1); 72 PushUp(L,R,rt); 73 } 74 } 75 int main() 76 { 77 char s[6]; 78 int n,i,cnt,size,pos; 79 while(~scanf("%d",&n)) 80 { 81 memset(vis,false,sizeof(vis)); 82 for(i=cnt=0;i<n;i++) 83 { 84 scanf(" %s",p[i].s); 85 if(p[i].s[0]!='m') 86 { 87 scanf("%d",&p[i].val); 88 x[cnt++]=p[i].val; 89 } 90 } 91 sort(x,x+cnt); 92 cnt=unique(x,x+cnt)-x; 93 Build(0,cnt-1,1); 94 for(i=size=0;i<n;i++) 95 { 96 if(p[i].s[0]=='a') 97 { 98 pos=lower_bound(x,x+cnt,p[i].val)-x; 99 if(!vis[pos]) 100 { 101 vis[pos]=true; 102 size++; 103 Update(pos,true,0,cnt-1,1); 104 } 105 } 106 else if(p[i].s[0]=='d') 107 { 108 pos=lower_bound(x,x+cnt,p[i].val)-x; 109 if(vis[pos]) 110 { 111 vis[pos]=false; 112 size--; 113 Update(pos,false,0,cnt-1,1); 114 } 115 } 116 else 117 { 118 if(size<2) 119 puts("0"); 120 else 121 printf("%d\n",tree[1].val); 122 } 123 } 124 } 125 return 0; 126 }
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