Problem: 2052A - Adrenaline Rush
Language: python

Solution 1 (runtime: 2249 ms):
import sys


def readline(type):
    return list(map(type, sys.stdin.readline().split(' ')))


def add_ans(a, b, ans, check):
    if check[a - 1][b - 1] != 0:
        return

    ans.append((a, b))
    check[a - 1][b - 1] = 1

# 1 2 3 4
# 1 2 3 4


def apply_stacked(stacked, ans, check):
    for a, b in reversed(stacked):
        add_ans(b, a, ans, check)


def useless_swaps(i_a, i_b, order, ans, check):
    if i_a == i_b:
        return

    for i in range(i_a, i_b):
        first = []
        last = []

        for next_i in range(i + 1, i_b + 1):
            a = order[i]
            b = order[next_i]

            if (
                check[a - 1][b - 1] + check[b - 1][a - 1] == 0
            ):
                first.append((a, b))
                last.append((a, b))
            else:
                break

        for a, b in first:
            ans.append((a, b))
            check[a - 1][b - 1] = 1
        for b, a in reversed(last):
            ans.append((a, b))
            check[a - 1][b - 1] = 1
# 1 2 3 4
# 1 3 2 4
# 1 2 3 4
# 1 2 4 3
# 4 1 2 3

def main():
    n, = readline(int)
    order = readline(int)

    check = [[0] * n for _ in range(n)]
    ans = []

    flag = True

    while flag:
        i_a = n - 1
        i_b = n - 1
        flag = False

        for i in range(n - 1, 0, -1):
            a = order[i - 1]
            b = order[i]

            if a < b:
                i_a = i - 1
            else:
                useless_swaps(i_a, i_b, order, ans, check)
                flag = True
                order[i - 1] = b
                order[i] = a
                ans.append((a, b))
                check[a - 1][b - 1] = 1
                break
        if not flag:
            useless_swaps(i_a, i_b, order, ans, check)

    print(len(ans))
    for a, b in reversed(ans):
        print(a, b, sep=' ')

if __name__ == '__main__':
    main()


Solution 2 (runtime: 1311 ms):
import math
mod=1000000007
mod1=998244353
inf=10**18+10

def swap(l1,x,y):
    a=l1[x]
    l1[x]=l1[y]
    l1[y]=a

t=1
for i in range(t):
    n=int(input())
    l1=list(map(int,input().split()))

    ind=[-1]*(n+1)
    for j in range(n):
        ind[l1[j]]=j

    l2=[j+1 for j in range(n)]
    st=set()

    ans=[]
    flag=1
    # print(l1)
    while flag:
        flag=0
        x=-1
        y=-1
        for j in range(n):
            for j1 in range(n-1):
                if l1[j1]<l1[j1+1]:
                    ans.append([l1[j1], l1[j1+1]])
                    swap(l1, j1, j1+1)
                if ind[l2[j1+1]]<ind[l2[j1]] and flag==0 and (l2[j1], l2[j1+1]) not in st:
                    # flag=1
                    x,y=j1, j1+1
                if ind[l2[j1+1]]>ind[l2[j1]]:
                    if (l2[j1], l2[j1+1]) not in st:
                        st.add((l2[j1+1],l2[j1]))
                        st.add((l2[j1],l2[j1+1]))
        # print(l1)
        for j in range(n):
            for j1 in range(n-1-j):
                if l1[j1]>l1[j1+1]:
                    ans.append([l1[j1], l1[j1+1]])
                    swap(l1, j1+1, j1)
        ans.reverse()
        if x!=-1:
            st.add((l2[y], l2[x]))
            # print(l2, ans)
            swap(l2, x, y)

    print(len(ans))
    for j in ans:
        print(*j)
    # print(ans)