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OI-source/history_source/信息学奥赛一本通/2.1.2.cpp
2023-08-03 09:22:52 +08:00

32 lines
469 B
C++

#include<iostream>
#include<string>
using namespace std;
void eraseZero(string &a)
{
while(a[0]=='0'&&a.size()>1) a.erase(0,1);
}
int main()
{
string a,b,c;
cin>>a>>b;
int x,j=0,ai,bi;
for(ai=a.size()-1,bi=b.size()-1;bi>=0;ai--,bi--)
{
x=(a[ai]-'0')-(b[bi]-'0')-j;
if(x<0) j=1,x+=10;
else j=0;
c=char('0'+x)+c;
}
while(ai>=0)
{
x=a[ai]-'0'-j;
if(x<0) j=1,x+=10;
else j=0;
c=char('0'+x)+c;
ai--;
}
eraseZero(c);
cout<<c<<endl;
return 0;
}