为什么高精度一直有问题啊

Archy_ @ 2024-08-20 18:02:15

#include<iostream>
using namespace std;
struct node {
    int a[100005], len = 0;
    node(int x = 0){
        while(x > 0){
            a[++ len] = x % 10;
            x /= 10;
        }
    }
    void print() {
        for(int i = len; i >= 1; i--) {
            cout << a[i];
        }
    }
};

node operator + (const node x, const node y){
    node z(0);
    z.len = max(x.len, y.len) + 2;
    for(int i = 1;i <= z.len; i ++) {
        z.a[i] += (x.a[i] + y.a[i]);
        if(z.a[i] > 9) {
            z.a[i + 1] += (z.a[i] / 10);
            z.a[i] %= 10;
        }
    }
    while(z.a[z.len] == 0) z.len--;
    return z;
} 

int main(){
    node a(1), b(2);
    a = a + b;
    a.print();
    a = a + a;
    a.print();
    return 0;
}

by yucheng0630 @ 2024-08-20 18:43:24

@hyf719346 壶关

#include <bits/stdc++.h>
#define int long long
const int maxn = 1e5 + 7;
using namespace std;
string a[maxn];
string add(string a, string b)
{
    int lena = a.size();
    int lenb = b.size();
    if (lena < lenb)
    {
        swap(a, b);
        swap(lena, lenb);
    }
    if (lena > lenb)
    {
        for (int i = 1; i <= lena - lenb; ++i)
        {
            b = '0' + b;
        }
    }
    int jinwei = 0;
    int num1;
    int num2;
    int num3;
    string ans = "";
    num3 = max(lena, lenb);
    int sum = 0;
    for (int i = num3 - 1; i >= 0; i--)
    {
        num1 = a[i] - '0';
        num2 = b[i] - '0';
        sum = num1 + num2 + jinwei;
        ans = char(sum % 10 + '0') + ans;
        jinwei = sum / 10;
    }
    if (jinwei != 0)
    {
        ans = '1' + ans;
    }
    return ans;
}
signed main()
{
    int n;
    cin >> n;
    a[1] = '1';
    a[2] = '2';
    for (int i = 3; i <= 5005; ++i)
    {
        a[i] = add(a[i - 1], a[i - 2]);
    }
    cout << a[n];
    return 0;
}

by Archy_ @ 2024-08-21 10:55:35

@yucheng0630 额，谢谢你了，但是问题已经解决了，a数组没有初始化。