高精度基础之减法格式1

#include<bits/stdc++.h> using namespace std; int main(void) { string s1,s2; cin>>s1>>s2; int a[505],b[505]; memset(a,0,sizeof(a)); memset(b,0,sizeof(b)); int len1=s1.length(); int len2=s2.length(); //关键！ if((len1<len2)||(len1==len2&&s1<s2)) { string tmp; tmp=s1; s1=s2; s2=tmp; printf("-"); } for(int i=0;i<len1;i++) a[i]=s1[len1-i-1]-'0'; for(int i=0;i<len2;i++) b[i]=s2[len2-i-1]-'0'; for(int i=0;i<len1;i++) { a[i]-=b[i]; if(a[i]<0) {a[i]+=10;a[i+1]--;} } while(a[len1-1]==0&&len1>=2) len1--; for(int i=len1-1;i>=0;i--) printf("%d",a[i]); printf("\n"); return 0; }