原题链接：http://poj.org/problem?id=2182
线段树。
从后往前寻找，首先是找第a[n]大的数，找到后记录到答案数组里并删除改叶子节点，然后在剩下的数字中再找a[n - 1]大的数，直到n次寻找完成。
View Code
1 #include <stdio.h> 2 #include <string.h> 3 #define lson (cur << 1) 4 #define rson (cur << 1 | 1) 5 #define INF 0x3f3f3f3f 6 #define N 8005 7 8 int a[N], ans[N]; 9 10 struct node 11 { 12 int l, r; 13 int len; 14 int v; 15 }tree[N << 2]; 16 17 void pushup(int cur) 18 { 19 tree[cur].len = tree[lson].len + tree[rson].len; 20 } 21 22 void query(int cur, int cnt, int loc) 23 { 24 if(tree[cur].l == tree[cur].r) 25 { 26 ans[loc] = tree[cur].v; 27 tree[cur].len = 0; 28 return ; 29 } 30 if(tree[lson].len >= cnt) 31 query(lson, cnt, loc); 32 else 33 query(rson, cnt - tree[lson].len, loc); 34 pushup(cur); 35 } 36 37 void build(int cur, int l, int r) 38 { 39 tree[cur].l = l, tree[cur].r = r; 40 if(l == r) 41 { 42 tree[cur].v = l; 43 tree[cur].len = 1; 44 return ; 45 } 46 int mid = (l + r) >> 1; 47 build(lson, l, mid); 48 build(rson, mid + 1, r); 49 pushup(cur); 50 } 51 52 int main() 53 { 54 int n, i; 55 scanf("%d", &n); 56 build(1, 1, n); 57 a[1] = 1; 58 for(i = 2; i <= n; i ++) 59 { 60 scanf("%d", &a[i]); 61 a[i] ++; 62 } 63 for(i = n; i >= 1; i --) 64 { 65 query(1, a[i], i); 66 } 67 for(i = 1; i <= n; i ++) 68 { 69 printf("%d\n", ans[i]); 70 } 71 return 0; 72 }