2020杭电多校第七场1009(Increasing and Decreasing)
题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=6852
Problem Description
Notice:Don't output extra spaces at the end of one line.
Given n,x,y, please construct a permutation of length n, satisfying that:
- The length of LIS(Longest Increasing Subsequence) is equal to x.
- The length of LDS(Longest Decreasing Subsequence) is equal to y .
If there are multiple possible permutations satisfying all the conditions, print the lexicographically minimum one.
Given n,x,y, please construct a permutation of length n, satisfying that:
- The length of LIS(Longest Increasing Subsequence) is equal to x.
- The length of LDS(Longest Decreasing Subsequence) is equal to y .
If there are multiple possible permutations satisfying all the conditions, print the lexicographically minimum one.
Input
The first line contains an integer T(1≤T≤100), indicating the number of test cases.
Each test case contains one line, which contains three integers n,x,y(1≤n≤1e5,1≤x,y≤n).
Each test case contains one line, which contains three integers n,x,y(1≤n≤1e5,1≤x,y≤n).
Output
For each test case, the first line contains ``YES'' or
``NO'', indicating if the answer exists. If the answer exists, output another
line which contains n integers, indicating the permutation.
Sample Input
4
10 1 10
10 10 1
10 5 5
10 8 8
Sample Output
YES
10 9 8 7 6 5 4 3 2 1
YES
1 2 3 4 5 6 7 8 9 10
YES
1 2 3 5 4 10 9 8 7 6
NO
题意:给出字典序最小的,长度为n的,最长上升子序列为x,最长下降子序列为y的序列
题解:n必须大于x*y+1并且n要小于x+y-1,之后将序列分成a块,设第i块长度为xi,则x1+x2+...+xa=n且xa=b,1<=xi<=b,并逐个枚举

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