给定长度为 m 的序列 T，求一个长度为 n 且字典序最小的排列.并且要求序列 T 为所求排列的子序列(1<=m<=n<=1e6)

思路：长度为n，看样例发现是只包含1~n的元素，因为是要求T只是子序列，直接用双指针比较谁小谁就在前面

def solve(A, n, m):
    vis, ans, B = [False for i in range(n+1)], [0 for i in range(n)], []
    for x in A:
        vis[x] = True
    for i in range(1,n+1):
        if not vis[i]:
            B.append(i)
    i, j, k = 0, 0, 0
    while i < len(A) and j < len(B):
        if A[i] < B[j]: ans[k], k, i = A[i], k+1, i+1
        else: ans[k], k, j = B[j], k+1, j+1
    while i < len(A): ans[k], k, i = A[i], k+1, i+1
    while j < len(B): ans[k], k, j = B[j], k+1, j+1
    return ans

n, m = map(int, input().split())
A = list(map(int, input().split()))
ans = solve(A, n, m)
for x in ans:
    print(x, end=' ')