Pair sort

n = int(input())
a = list(map(int, input().split()))

s = []
for i in range(0, 2*n, 2):
    if a[i] != a[i+1]:
        
        for j in range(i+1, 2*n):
            
            if a[j] == a[i]:
                
                s.append((i+2, j+1))
                a[i+1], a[j] = a[j], a[i+1]
                break

print(len(s))

for i in s:
    print(i[0], i[1])

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED