c++,java,python大数加法

大数加法

c++

#include 
#include 
#include 
using namespace std;
#define MAXN 1000
int a[MAXN],b[MAXN];
int main(int argc, const char * argv[])
{
    string str1,str2;//保存输入
    long int len1,len2;
    long int i,j,k;
    int up;

    /*输入流程*/
    cin>>str1>>str2;

    /*初始化各量*/
    len1 = str1.length();
    len2 = str2.length();
    memset(a, 0, sizeof(a));
    memset(b, 0, sizeof(b));

    /*注意，必须倒着保存数据*/
    for (i = len1 - 1, k = 0; i != -1; -- i)
    {
        a[k] = str1[i] - '0';
        k++;
    }
    for (j = len2 - 1, k = 0; j != -1; -- j)
    {
        b[k] = str2[j] - '0';
        k++;
    }
    for (i = 0, up = 0; i < MAXN; ++ i)
    {
        a[i] = a[i] + b[i] + up;
        up = a[i] / 10;
        a[i] %= 10;
    }
    for (i = MAXN - 1; i != -1; -- i)
    {
        if (a[i])
        {
            break;
        }
    }
    for (k = i; k != -1; --k)
    {
        cout<<a[k];
    }
    return 0;
    }

java

import java.math.BigInteger;
import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        BigInteger a, b;
        Scanner in = new Scanner(System.in);
            a = in.nextBigInteger();
            b = in.nextBigInteger();
            System.out.println(a + " + " + b + " = " + a.add(b) );
            System.out.println();
    }
} 

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python

a = int(input());b = int(input());print(a+b);