1935B - Informatics in MAC - CodeForces Solution

for _ in range(int(input())):
    n=int(input())
    l=list(map(int,input().split()))
    d={}
    for ele in l:
        if(ele not in d):
            d[ele]=1
        else:
            d[ele]+=1
    mex=0
    for i in range(n+1):
        if(i not in d):
            mex=i
            break
    if(mex==0):
        print(2)
        print(1,1)
        print(2,n)
        continue
    d={}
    ans=[]
    left=0
    for i in range(n):
        if(l[i]<mex):
            d[l[i]]=1
        if(len(d)==mex):
            ans.append([left+1,i+1])
            left=i+1
            d={}
    ans[len(ans)-1][1]=n
    if(len(ans)<2):
        print(-1)
    else:
        print(len(ans))
        for val in ans:
            print(val[0],val[1])