Beginner level Luogu 2 [branch structure] problem list solution

Catalog

Leap year judgment

Obesity

Three digit sorting

Unhappy Jinjin

Buy a pencil

ISBN number

  The voyage of a small fish

Trigonometric functions

ABC

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​​​​​​【 introduction 2】 Branching structure - List of questions - Luogu | New ecology of computer science education (luogu.com.cn)

Leap year judgment

• ①400 Multiple
• ② yes 4 But it's not 100 Multiple

if((n%4==0&&n%100!=0)||n%400==0)

Obesity

• At output time , Please round to six digits Significant figures Output , If there is a suffix in the decimal part  00, Do not output suffixes  00.
• You can use %g

(106 Bar message ) Keep valid digits ; After decimal point n position ;_ Yang Yi's blog -CSDN Blog

printf("%.6g\nOverweight", criterion);

Three digit sorting

 

Unhappy Jinjin

#include<iostream>
#include<iomanip>
using namespace std;
int main() {
	int a[7], b[7],sum[7],max=0,k;
	for (int i = 0; i < 7; i++)
	{
		cin >> a[i] >> b[i];
		
	}
	bool happy = true;
	for (int i = 0; i < 7; i++)
	{
		sum[i] = a[i] + b[i];
		if (sum[i] > 8)
		{
			happy = false;
		}
		if (sum[i] > max)
		{
			max = sum[i];
			k = i;
		}
	}
	if (happy == true)
		cout << "0";
	if (happy == false)
		cout << k+1;



	return 0;
}

Buy a pencil

#include<iostream>
#include<iomanip>
#include<math.h>
#include<algorithm>
using namespace std;
int main() {
	int n,a;
	double pencil[3], sum[3];
	long long price[3];
	cin >> n;
	for (int i = 0; i < 3; i++)
	{
		cin >> pencil[i] >> sum[i];
	}
	for (int i = 0; i < 3; i++)
	{
		price[i]=ceil(n / pencil[i])*sum[i];
	}
	cout<<min(price[2],min(price[0], price[1]));
	return 0;
}

ISBN number

#include<iostream>
#include<string>
#include<math.h>
#include<algorithm>
using namespace std;
int main() {

	string a;
	int sum = 1,sbm=0;
	char x = 'X';
		cin >> a;
	for (int i = 0; i < 11; i++)
	{
		if (isdigit(a[i]))
		{
			sbm += (a[i]-'0') * sum;
			++sum;
		}
	}
	sbm %= 11;
	if (a[12] == 'X'&&sbm == 10)
	{
		cout << "Right";
	}
	else if (a[12]!='X' && a[12]-'0' == sbm)
	{
		cout << "Right";
	}
	else
	{
		for (int i = 0; i < 12; i++)
		{
			cout << a[i];
		}
		if (sbm == 10)
			cout << "X";
		else
		cout << sbm;
	}
	return 0;
}

  The voyage of a small fish

#include<iostream>

using namespace std;

int main() {
	int n, x,a=0;
	cin >> x >> n;
	// Direct overall arrangement 
	while (n--)
	{
		if (x != 6 && x != 7)
			a += 250;
		x++;
		if (x == 8)
			x = 1;

	}
	cout << a;
	return 0;
}

Trigonometric functions

#include<iostream>
#include<algorithm>
#include<math.h>
using namespace std;

int main() {
	int a, b, c,min1,max1;
	cin >> a >> b >> c;
	min1 = min(c, min(a, b));
	max1 = max(c, max(a, b));
// right triangle   Minimum acute angle sin value   It must be   The smallest edge / The largest edge 
	for (int i = 2; i <= min1; i++) // Factor finding , elimination .
	{
		if (min1%i == 0 && max1%i == 0)
		{
			min1 = min1 / i;
			max1 = max1 / i;
		}
	}
	cout << min1 << "/" << max1;
	return 0;
}

 

ABC

#include<iostream>
#include<iomanip>
#include<algorithm>
#include<string>
using namespace std;
int main()
{
	string a;
	int A[3];
	for (int i = 0; i < 3; i++)
	{
		cin >> A[i];
	}
	cin >> a;
	sort(A, A + 3);
	for (int i = 0; i < 3; i++)
	{
		cout << A[a[i] - 'A']<<" ";
	}
	return 0;
}