原题链接：http://www.tyvj.cn/p/1730
树套树。。。
如下：
1 #include<cstdio> 2 #include<cstdlib> 3 #include<cstring> 4 #include<algorithm> 5 #define lc root<<1 6 #define rc root<<1|1 7 #define INF 0x3f3f3f3f 8 #define _max(a,b) ((a)>(b)?(a):(b)) 9 #define _min(a,b) ((a)>(b)?(b):(a)) 10 const int Max_N = 50100; 11 struct SBT *null; 12 struct SBT{ 13 int v, s, c; 14 SBT *ch[2]; 15 SBT(int _v = 0) : v(_v){ 16 c = s = 1; 17 ch[0] = ch[1] = null; 18 } 19 inline void push_up(){ 20 s = ch[0]->s + ch[1]->s + c; 21 } 22 inline int cmp(int x) const{ 23 return v == x ? -1 : x > v; 24 } 25 }stack[Max_N << 5], *ptr[Max_N << 2]; 26 int sz = 0, sum = 0, arr[Max_N]; 27 void init(){ 28 null = &stack[sz++]; 29 null->s = null->c = 0; 30 } 31 inline void rotate(SBT* &x, int d){ 32 SBT *k = x->ch[!d]; 33 x->ch[!d] = k->ch[d]; 34 k->ch[d] = x; 35 k->s = x->s;; 36 x->push_up(); 37 x = k; 38 } 39 void Maintain(SBT* &x, int d){ 40 if (x->ch[d] == null) return; 41 if (x->ch[d]->ch[d]->s > x->ch[!d]->s){ 42 rotate(x, !d); 43 } else if (x->ch[d]->ch[!d]->s > x->ch[d]->s){ 44 rotate(x->ch[d], d), rotate(x, !d); 45 } else { 46 return; 47 } 48 Maintain(x, 0), Maintain(x, 1); 49 } 50 void insert(SBT* &x, int v){ 51 if (x == null){ 52 x = &stack[sz++]; 53 x->v = v; 54 x->ch[0] = x->ch[1] = null; 55 } else { 56 x->s++; 57 int d = x->cmp(v); 58 if (-1 == d){ 59 x->c++; 60 return; 61 } 62 insert(x->ch[d], v); 63 x->push_up(); 64 Maintain(x, d); 65 } 66 } 67 void del(SBT* &x, int v){ 68 if (x == null) return; 69 int d = x->cmp(v); 70 x->s--; 71 if (-1 == d){ 72 if (x->c > 1){ 73 x->c--; 74 } else if (x->ch[0] == null || x->ch[1] == null){ 75 x = x->ch[0] != null ? x->ch[0] : x->ch[1]; 76 } else { 77 SBT *ret = x->ch[1]; 78 for (; ret->ch[0] != null; ret = ret->ch[0]); 79 del(x->ch[1], x->v = ret->v); 80 } 81 } else { 82 del(x->ch[d], v); 83 } 84 if (x != null) x->push_up(); 85 } 86 int sbt_rank(SBT *x, int v){ 87 int t = 0, cur = 0; 88 for (; x != null;){ 89 t = x->ch[0]->s; 90 if (v == x->v) return cur + t; 91 else if (v < x->v) x = x->ch[0]; 92 else cur += t + x->c, x = x->ch[1]; 93 } 94 return cur; 95 } 96 int sbt_pred(SBT *x, int v){ 97 int t = -1; 98 for (; x != null;){ 99 if (x->v < v){ 100 t = x->v; 101 x = x->ch[1]; 102 } 103 else x = x->ch[0]; 104 } 105 return t == -1 ? -INF : t; 106 } 107 int sbt_succ(SBT *x, int v){ 108 int t = -1; 109 for (; x != null;){ 110 if (x->v > v){ 111 t = x->v; 112 x = x->ch[0]; 113 } 114 else x = x->ch[1]; 115 } 116 return t == -1 ? INF : t; 117 } 118 void seg_built(int root, int l, int r){ 119 ptr[root] = null; 120 for (int i = l; i <= r; i++) insert(ptr[root], arr[i]); 121 if (l == r) return; 122 int mid = (l + r) >> 1; 123 seg_built(lc, l, mid); 124 seg_built(rc, mid + 1, r); 125 } 126 void seg_rank(int root, int l, int r, int x, int y, int v){ 127 if (x > r || y < l) return; 128 if (x <= l && y >= r){ 129 sum += sbt_rank(ptr[root], v); 130 return; 131 } 132 int mid = (l + r) >> 1; 133 seg_rank(lc, l, mid, x, y, v); 134 seg_rank(rc, mid + 1, r, x, y, v); 135 } 136 void seg_modify(int root, int l, int r, int pos, int v){ 137 if (pos > r || pos < l) return; 138 del(ptr[root], arr[pos]); 139 insert(ptr[root], v); 140 if (l == r) return; 141 int mid = (l + r) >> 1; 142 seg_modify(lc, l, mid, pos, v); 143 seg_modify(rc, mid + 1, r, pos, v); 144 } 145 int seg_pred(int root, int l, int r, int x, int y, int v){ 146 if (x > r || y < l) return -INF; 147 if (x <= l && y >= r) return sbt_pred(ptr[root], v); 148 int mid = (l + r) >> 1; 149 int v1 = seg_pred(lc, l, mid, x, y, v); 150 int v2 = seg_pred(rc, mid + 1, r, x, y, v); 151 return _max(v1, v2); 152 } 153 int seg_succ(int root, int l, int r, int x, int y, int v){ 154 if (x > r || y < l) return INF; 155 if (x <= l && y >= r) return sbt_succ(ptr[root], v); 156 int mid = (l + r) >> 1; 157 int v1 = seg_succ(lc, l, mid, x, y, v); 158 int v2 = seg_succ(rc, mid + 1, r, x, y, v); 159 return _min(v1, v2); 160 } 161 void gogo(int n, int a, int b, int k){ 162 int mid, l = 0, r = 100000000; 163 while (l < r){ 164 sum = 0; 165 mid = (l + r) >> 1; 166 seg_rank(1, 1, n, a, b, mid); 167 if (sum < k) l = mid + 1; 168 else r = mid; 169 } 170 printf("%d ", l - 1); 171 } 172 int main(){ 173 #ifdef LOCAL 174 freopen("in.txt", "r", stdin); 175 freopen("out.txt", "w+", stdout); 176 #endif 177 init(); 178 int i, n, m, a, b, c, d; 179 scanf("%d %d", &n, &m); 180 for (i = 1; i <= n; i++) scanf("%d", &arr[i]); 181 seg_built(1, 1, n); 182 while (m--){ 183 scanf("%d", &a); 184 switch (a){ 185 case 1: 186 sum = 1; 187 scanf("%d %d %d", &b, &c, &d); 188 seg_rank(1, 1, n, b, c, d); 189 printf("%d ",sum); 190 break; 191 case 2: 192 scanf("%d %d %d", &b, &c, &d); 193 gogo(n, b, c, d); 194 break; 195 case 3: 196 scanf("%d %d", &b, &c); 197 seg_modify(1, 1, n, b, c), arr[b] = c; 198 break; 199 case 4: 200 scanf("%d %d %d", &b, &c, &d); 201 printf("%d ", seg_pred(1, 1, n, b, c, d)); 202 break; 203 case 5: 204 scanf("%d %d %d", &b, &c, &d); 205 printf("%d ", seg_succ(1, 1, n, b, c, d)); 206 break; 207 } 208 } 209 return 0; 210 }