delete pics to save space

history_source/信息学奥赛一本通/2.1.2.cpp

@@ -0,0 +1,31 @@
+#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;
+}