//equation.cpp // //Created by Leo on 17/1/29 //Copyright © 2017年 Leo. All rights reserved. // /Users/Leo/Documents/大二 #include #include #include using namespace std; int comparechar(char & a, char & b)//比较字符串的一位数并相减 { if(a < b) { a = char( a + 10 );//借十 a = char( a - (b - '0') ); return -1; } else { a = char( a - (b - '0') ); return 0;
}
}
void comparestr(string & a, string & b, string &c)//比较两个字符串的长度，并不断比较每位数 { int i; int j; string temp; c = "+"; if(a.length() < b.length()) { temp = a; a = b; b = temp; c = "-"; } if(a.length() == b.length() && a < b) { temp = a; a = b; b = temp; c = "-"; }
for( i = a.size()-1, j = b.size()-1; j >= 0; i--, j--)
{
int t;
t = comparechar(a[i], b[j]);
if(t == -1 && i > 0)
{
a[i-1]--;
}
}
while(i > 0)//借
{
if(a[i] < '0')
{
a[i] = char (a[i] + 10);
a[i-1]--;
}
i--;
}
int index = 0;
for(i = 0; i < a.size(); i++)//去零
{
if(a[i] != '0')
break;
index++;
}
string s(a, index, a.size()-index);
a = s;
}
int main(int argc, const char * argv[] ){
string str1,str2,str3;
str1 = argv[1];
str2 = argv[2];
//comparechar(, <#char &b#>)
comparestr(str1, str2, str3);
if(str3 == "-")
cout << str3 + str1 <<endl;
else
cout << str1 <<endl;
return 0;
}