The dumbest code I've ever written

Preface

Everyone has hair on their body Everyone’s code is stupid, and coincidentally, I have it too! As soon as I saw the CSDN activity "What is the stupidest code you have ever written?" 》, I immediately wanted to participate to tell everyone about some of my stupid codes and the shortcomings of these codes, and how we can avoid them. Surprise

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Stupid code - 1

Everyone should be familiar with intervals! It's OK to use the prefix sum, but I...

#include <bits/stdc++.h>
using namespace std;
int a[100005]
int main()
{
    
    
	int n;
	cin>>n;
	for(int i=1; i<=n; i++) cin>>a[i];
	int sum=0;
	int l,r;
	cin>>l>>r;
	for(int i=l; i<=r; i++) sum+=a[i];
	cout<<sum;
	return 0;
}

Violence works wonders!
Finally, I would like to mention a TLE... The most appropriate thing to do is to use the prefix sum (will be discussed later):

#include <iostream>
using namespace std;
int a[100005],n,q,l,r,sa[100005];
int main()
{
    
    
    cin>>n;
    for(int i=1; i<=n; i++)
    {
    
    
    	cin>>a[i];
    	sa[i]=a[i]+sa[i-1];
    }
    cin>>l>>r;
    cout<<sa[r]-sa[l-1]<<endl;
    return 0;
}

Stupid Code - 2

A+B Problem is familiar to everyone, I should have written:

#include <iostream>
using namespace std;

int main()
{
    
    
	int a,b;
	cin>>a>>b;
	cout<<a+b;
	return 0;
}

But what I wrote is:

#include <iostream>
using namespace std;

int main()
{
    
    
	int 博主,牛掰;
	cin>>博主>>牛掰;
	cout<<博主+牛掰;
	return 0;
}

(Note: Statements are very dangerous in C++)

Stupid Code - 3

The first time I wrote a binary tree + preorder traversal was the first time. When writing a binary tree, I did not use new to give the binary tree memory space, as follows:

#include <iostream>
using namespace std;

struct Node {
    
    
    int value;
    Node* left;
    Node* right;
}; 
void qianxv(Node* root) {
    
    
    if (root == nullptr) {
    
    
        return;
    }

    cout << root->value << " "; 
    preOrderTraversal(root->left);
    preOrderTraversal(root->right);
}
int main() {
    
    
    Node* tree;
    tree->value = 1;
    tree->left->value = 3;
    tree->left->left->value = 114;
    tree->left->right->value = 114514;

    cout << "前序遍历结果：" << endl;
    preOrderTraversal(tree);

    return 0;
}

喜提 $ERROR$ One piece!

$correctly$ correctness:

#include <iostream>
using namespace std;

struct Node {
    
    
    int value;
    Node* left;
    Node* right;
}; 
void qianxv(Node* root) {
    
    
    if (root == nullptr) {
    
    
        return;
    }

    cout << root->value << " "; 
    preOrderTraversal(root->left);
    preOrderTraversal(root->right);
}
int main() {
    
    
    Node* tree = new Node();
    tree->value = 1;
    tree->left = new Node();
    tree->left->value = 3;
    tree->left->left = new Node();
    tree->left->left->value = 114;
    tree->left->right = new Node();
    tree->left->right->value = 114514;

    cout << "前序遍历结果：" << endl;
    preOrderTraversal(tree);

    return 0;
}

Blogger’s feelings:Click me

remind!

Be sure to use the keyword new to open up space for the pointer!

Stupid Code - 4

Question:
$$\sum _{i=1}^{\mathcal{N}}f\left(i\right)$$
Further definition: {\color{Red} f(N)=N approximate number} } }
$$f(\mathcal{N})=The\; number\; of\; divisors\; of\; N$$
I thought:

#include <iostream>
using namespace std;

int main() {
    
    
    int n;
    cin >> n;
    int sum = 0;
    for (int i = 1; i <= n; i++) {
    
    
        for (int j = 1; j*j <= i; j++) {
    
    
            if (i % j == 0) {
    
    
                sum++;
                if (j != i / j) sum++;
            }
        }
    }
    cout << sum << endl;
    return 0;
}

但 $TLE$ 了呜呜

The correct one should be:

#include <iostream>
using namespace std;
int main() {
    
    
    int n,sum = 0;
    cin >> n;
    for (int i = 1; i <= n; i++) sum+=n/i;
    cout << sum << endl;
    return 0;
}

$Be\; vigilant$ Blogger’s feelings:Click me

Summarize

This article talks about my stupid code, I hope you won’t imitate it!
No. 1379:
Don’t answer!
Don’t answer! !
Don’t answer! ! !

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