全WA求助

P1009 [NOIP1998 普及组] 阶乘之和

fish_gugu @ 2023-04-20 20:17:21

#include <iostream>
#include <string>
using namespace std;

int mul[1010];
int sum[1000010];

void addBIG(int x[], int y[], int z[])
{
    z[0] = max(x[0], y[0]);
    for (int i = 1; i <= z[0]; i++)
         z[i] = x[i] + y[i];
    for (int i = 1; i <= z[0]; i++)
    {
          z[i + 1] += z[i] / 10;
          z[i] %= 10;
          if (z[z[0] + 1] > 0) z[0]++;
    }
}

void i2BIG(int n, int a[]) 
{
    int la = 0;
    while (n > 0)
    {
          la++;
          a[la] = n % 10;
          n /= 10;
    }
    if (la == 0) la++;
    a[0] = la;  
}

void printBIG(int a[]) 
{
    int la = a[0];  
    for (int i = la; i >= 1; i--) 
    {
        cout << a[i];
    }
    cout << endl; 
}

void mulBIG(int x[], int y, int z[])
{
    z[0] = x[0];
    for (int i = 1; i <= z[0]; i++) 
        z[i] = x[i] * y;
    for (int i = 1; i <= z[0]; i++) 
    {
        z[i + 1] += z[i] / 10;
        z[i] %= 10;
        if (z[z[0] + 1] > 0) z[0]++;
    }
}

int main()
{
    int n;
    cin >> n;
    i2BIG(1,mul);
    for(int i = 1;i <= n;i++)
    {
        for(int j = 1;j <= i;j++)
        {
            mulBIG(mul,j,mul);
        }
        addBIG(mul,sum,sum);
        i2BIG(1,mul);
    }
    printBIG(sum);
    return 0;
}

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