字符串模拟
n,q=map(int,input().split())
s='?'+input()
for _ in range(0,q):
l,r=map(int,input().split())
s1=s[:l]
s2=s[l:r+1]
s3=s[r+1:]
tmp=[i+i for i in s2]
s4=''.join(tmp)
s=s1+s4+s3
print(s[1:])

字符串模拟
n,q=map(int,input().split())
s='?'+input()
for _ in range(0,q):
l,r=map(int,input().split())
s1=s[:l]
s2=s[l:r+1]
s3=s[r+1:]
tmp=[i+i for i in s2]
s4=''.join(tmp)
s=s1+s4+s3
print(s[1:])