C++大数模板 BigInteger

来源：互联网发布：数据采集卡安装编辑：程序博客网时间：2024/05/16 17:31

网上搜集的一份写的灰常漂亮的大数模板。Mark之~~~~

看不懂的自行补脑了 +_+

#include <cstdio>#include <algorithm>#include <cstring>using namespace std;struct BigInteger{    int A[25];    enum{MOD = 10000};    BigInteger(){memset(A, 0, sizeof(A)); A[0]=1;}    void set(int x){memset(A, 0, sizeof(A)); A[0]=1; A[1]=x;}    void print(){        printf("%d", A[A[0]]);        for (int i=A[0]-1; i>0; i--){            if (A[i]==0){printf("0000"); continue;}            for (int k=10; k*A[i]<MOD; k*=10) printf("0");            printf("%d", A[i]);        }        printf("\n");    }    int& operator [] (int p) {return A[p];}    const int& operator [] (int p) const {return A[p];}    BigInteger operator + (const BigInteger& B){        BigInteger C;        C[0]=max(A[0], B[0]);        for (int i=1; i<=C[0]; i++)            C[i]+=A[i]+B[i], C[i+1]+=C[i]/MOD, C[i]%=MOD;        if (C[C[0]+1] > 0) C[0]++;        return C;    }    BigInteger operator * (const BigInteger& B){        BigInteger C;        C[0]=A[0]+B[0];        for (int i=1; i<=A[0]; i++)            for (int j=1; j<=B[0]; j++){                C[i+j-1]+=A[i]*B[j], C[i+j]+=C[i+j-1]/MOD, C[i+j-1]%=MOD;            }        if (C[C[0]] == 0) C[0]--;        return C;    }};int main() {    BigInteger a, b;    a.set(1); b.set(1);    (a+b).print();    return 0;}