//高精度减法

#include <bits/stdc++.h>

using namespace std;

string sa,sb;

int na[1005],i,j,nb[1005],nc[1005];

int lena,lenb,lenc;

int main()

{

    cin>>sa>>sb;

    lena=sa.size(); lenb=sb.size(); lenc=max(lena,lenb);

    if(lena<lenb || (lena==lenb && sa<sb)){

        swap(sa,sb);

        swap(lena,lenb);

        cout<<"-";

    }

        for(i=1;i<=lena;i++) na[i]=sa[lena-i]-48;  

        for(i=1;i<=lenb;i++) nb[i]=sb[lenb-i]-48;   

        for(i=1;i<=lenc;i++){

            nc[i]=na[i]-nb[i];

            if(nc[i]<0){

                na[i+1]--;

                nc[i]+=10;

            }

        }

    while(nc[lenc]==0 && lenc>1) lenc--;    

    for(i=lenc;i>=1;i--) cout<<nc[i];

    return 0;

}

标签：lenc,lenb,lena,高精度,nc,sb,sa,减法
来源： https://blog.csdn.net/sunxinzehh/article/details/118710794