Splay！

  1 #include<cstdio>
  2 #include<cstdlib>
  3 const int mod =1000000007;
  4 const int inf  = ~0u>>2;
  5 const int maxn = 200010;
  6 int lim;
  7 struct SplayTree {
  8 19.    int sz[maxn];
  9 20.    int ch[maxn][2];
 10 21.    int pre[maxn];
 11 22.    int rt,top;
 12 23.    inline void up(int x){
 13 24.        sz[x]  = cnt[x]  + sz[ ch[x][0] ] + sz[ ch[x][1] ];
 14 25.    }
 15 26.    inline void Rotate(int x,int f){
 16 27.        int y=pre[x];
 17 28.        ch[y][!f] = ch[x][f];
 18 29.        pre[ ch[x][f] ] = y;
 19 30.        pre[x] = pre[y];
 20 31.        if(pre[x]) ch[ pre[y] ][ ch[pre[y]][1] == y ] =x;
 21 32.        ch[x][f] = y;
 22 33.        pre[y] = x;
 23 34.        up(y);
 24 35.    }
 25 36.    inline void Splay(int x,int goal){//将x旋转到goal的下面
 26 37.        while(pre[x] != goal){
 27 38.            if(pre[pre[x]] == goal) Rotate(x , ch[pre[x]][0] == x);
 28 39.            else   {
 29 40.                int y=pre[x],z=pre[y];
 30 41.                int f = (ch[z][0]==y);
 31 42.                if(ch[y][f] == x) Rotate(x,!f),Rotate(x,f);
 32 43.                else Rotate(y,f),Rotate(x,f);
 33 44.            }
 34 45.        }
 35 46.        up(x);
 36 47.        if(goal==0) rt=x;
 37 48.    }
 38 49.    inline void RTO(int k,int goal){//将第k位数旋转到goal的下面
 39 50.        int x=rt;
 40 51.        while(sz[ ch[x][0] ] != k-1) {
 41 52.            if(k < sz[ ch[x][0] ]+1) x=ch[x][0];
 42 53.            else {
 43 54.                k-=(sz[ ch[x][0] ]+1);
 44 55.                x = ch[x][1];
 45 56.            }
 46 57.        }
 47 58.        Splay(x,goal);
 48 59.    }
 49 60.    inline void vist(int x){
 50 61.        if(x){
 51 62.            printf("结点%2d : 左儿子  %2d   右儿子  %2d   %2d sz=%d\n",x,ch[x][0],ch[x][1],val[x],sz[x]);
 52 63.            vist(ch[x][0]);
 53 64.            vist(ch[x][1]);
 54 65.        }
 55 66.    }
 56 67.    inline void Newnode(int &x,int c){
 57 68.        x=++top;
 58 69.        ch[x][0] = ch[x][1] = pre[x] = 0;
 59 70.        sz[x]=1; cnt[x]=1;
 60 71.        val[x] = c;
 61 72.    }
 62 73.    inline void init(){
 63 74.        ans=0;type=-1;
 64 75.        ch[0][0]=ch[0][1]=pre[0]=sz[0]=0;
 65 76.        rt=top=0; cnt[0]=0;
 66 77.        Newnode(rt,-inf);
 67 78.        Newnode(ch[rt][1],inf);
 68 79.        pre[top]=rt;
 69 80.        sz[rt]=2;
 70 81.    }
 71 82.    inline void Insert(int &x,int key,int f){
 72 83.        if(!x) {
 73 84.            Newnode(x,key);
 74 85.            pre[x]=f;
 75 86.            Splay(x,0);
 76 87.            return ;
 77 88.        }
 78 89.        if(key==val[x]){
 79 90.            cnt[x]++;
 80 91.            sz[x]++;
 81 92.            return ;
 82 93.        }else if(key<val[x]) {
 83 94.            Insert(ch[x][0],key,x);
 84 95.        } else {
 85 96.            Insert(ch[x][1],key,x);
 86 97.        }
 87 98.        up(x);
 88 99.    }
 89 100.    void Del(){
 90 101.         int t=rt;
 91 102.         if(ch[rt][1]) {
 92 103.             rt=ch[rt][1];
 93 104.             RTO(1,0);
 94 105.             ch[rt][0]=ch[t][0];
 95 106.             if(ch[rt][0]) pre[ch[rt][0]]=rt;
 96 107.         }
 97 108.         else rt=ch[rt][0];
 98 109.         pre[rt]=0;
 99 110.         up(rt);
100 111.    }
101 112.    void findpre(int x,int key,int &ans){
102 113.        if(!x)  return ;
103 114.        if(val[x] <= key){
104 115.            ans=x;
105 116.            findpre(ch[x][1],key,ans);
106 117.        } else
107 118.            findpre(ch[x][0],key,ans);
108 119.    }
109 120.    void findsucc(int x,int key,int &ans){
110 121.        if(!x) return ;
111 122.        if(val[x]>=key) {
112 123.            ans=x;
113 124.            findsucc(ch[x][0],key,ans);
114 125.        } else
115 126.            findsucc(ch[x][1],key,ans);
116 127.    }
117 128.    void solve() {
118 129.        int a,b,x,y;
119 130.        scanf("%d%d",&a,&b);
120 131.        if(a==type || sz[rt]==2){
121 132.
122 133.            Insert(rt,b,0),type=a;
123 134.            //printf("type=%d\n",type);
124 135.        }
125 136.        else {
126 137.            findpre(rt,b,x);
127 138.            findsucc(rt,b,y);
128 139.            if(abs(val[x]-b) <= abs(val[y]-b)) {
129 140.                ans+=abs(val[x]-b);
130 141.                ans%=mod;
131 142.                Splay(x,0);
132 143.                Del();
133 144.            }
134 145.            else {
135 146.                ans+=abs(val[y]-b);
136 147.                ans%=mod;
137 148.                Splay(y,0);
138 149.                Del();
139 150.            }
140 151.        }
141 152.        //spt.vist(rt);
142 153.    }
143 154.    int cnt[maxn];
144 155.    int val[maxn];
145 156.    int type;
146 157.    int ans;
147 158.}spt;
148 159.int main()
149 160.{
150 161.    int n;
151 162.    scanf("%d",&n);
152 163.    spt.init();
153 164.    while(n--)  spt.solve();
154 165.    printf("%d\n",spt.ans);
155 166.    return 0;
156 }  

Splay！