【HYSBZ】2002 Bounce 弹飞绵羊

  1 #include<cstdio>

  2 #include<cstring>

  3 #include<iostream>

  4 #define MAXN 200010

  5 using namespace std;

  6 struct LCT {

  7     int bef[MAXN];

  8     int next[MAXN][2], pre[MAXN], key[MAXN], sum[MAXN];

  9     void Init() {

 10         memset(next, 0, sizeof(next));

 11         memset(pre, 0, sizeof(pre));

 12     }

 13     inline void PushUp(int x) {

 14         sum[x] = key[x] + sum[next[x][0]] + sum[next[x][1]];

 15     }

 16     void Rotate(int x, int kind) {

 17         int y, z;

 18         y = pre[x];

 19         z = pre[y];

 20         next[y][!kind] = next[x][kind];

 21         pre[next[x][kind]] = y;

 22         next[z][next[z][1] == y] = x;

 23         pre[x] = z;

 24         next[x][kind] = y;

 25         pre[y] = x;

 26         PushUp(y);

 27     }

 28     void Splay(int x) {

 29         int rt;

 30         for (rt = x; pre[rt]; rt = pre[rt])

 31             ;

 32         if (rt != x) {

 33             bef[x] = bef[rt];

 34             bef[rt] = 0;

 35             while (pre[x]) {

 36                 if (next[pre[x]][0] == x)

 37                     Rotate(x, 1);

 38                 else

 39                     Rotate(x, 0);

 40             }

 41             PushUp(x);

 42         }

 43     }

 44     void Access(int x) {

 45         int father;

 46         for (father = 0; x; x = bef[x]) {

 47             Splay(x);

 48             bef[next[x][1]] = x;

 49             bef[father] = 0;

 50             pre[next[x][1]] = 0;

 51             next[x][1] = father;

 52             pre[father] = x;

 53             father = x;

 54             PushUp(x);

 55         }

 56     }

 57     int Query(int x) {

 58         Access(x);

 59         Splay(x);

 60         return sum[next[x][0]];

 61     }

 62     void Cut(int x) {

 63         Access(x);

 64         Splay(x);

 65         bef[next[x][0]] = bef[x];

 66         bef[x] = 0;

 67         pre[next[x][0]] = 0;

 68         next[x][0] = 0;

 69     }

 70     void Join(int x, int y) {

 71         Cut(x);

 72         bef[x] = y;

 73     }

 74 } lct;

 75 int K[MAXN];

 76 int INT() {

 77     int res;

 78     char ch;

 79     while (ch = getchar(), !isdigit(ch))

 80         ;

 81     for (res = ch - '0'; ch = getchar(), isdigit(ch);)

 82         res = res * 10 + ch - '0';

 83     return res;

 84 }

 85 int main() {

 86     int n, i;

 87     int q, x, y, cmd;

 88     while (~scanf("%d", &n)) {

 89         lct.Init();

 90         for (i = 1; i <= n; i++) {

 91             K[i] = INT();

 92             if (i + K[i] > n)

 93                 lct.bef[i] = 0;

 94             else

 95                 lct.bef[i] = i + K[i];

 96             lct.key[i] = lct.sum[i] = 1;

 97         }

 98         q = INT();

 99         while (q--) {

100             cmd = INT(), x = INT() + 1;

101             if (cmd == 1)

102                 printf("%d\n", lct.Query(x) + 1);

103             else {

104                 y = INT();

105                 K[x] = y;

106                 if (x + y > n)

107                     y = 0;

108                 else

109                     y = x + y;

110                 lct.Join(x, y);

111             }

112         }

113     }

114     return 0;

115 }