P11两数比大小

#include <iostream>
using namespace std;
int main() {
	int a,b;
	cin>>a>>b;
	if(a < b){
	   a = b;
	}
	cout<<a;
	return 0;
}

P12判断能否被3,5,7整除

#include <iostream>
using namespace std;
int main() {
	int n; cin>>n;
	if(n%3==0){
		cout<<"3 ";
	}
	if(n%5==0){
		cout<<"5 ";
	}
	if(n%7==0){
		cout<<"7 ";
	}
	if(n%3!=0 && n%5!=0 && n%7!=0){
		cout<<"n";
	}
	return 0;
}

P13海伦公式

#include<iostream>
#include<iomanip>
#include<cmath>
using namespace std;

int main() {
	double a,b,c;
	cin>>a>>b>>c;
	if(a+b > c && a+c > b && b+c>a) {
		double p = (a+b+c) / 2;
		double s = sqrt(p*(p-a)*(p-b)*(p-c));
		cout<<fixed<<setprecision(1)<<s;
	} else cout<<0;
	return 0;
}

P14三角形类别

#include <iostream>
using namespace std;
int main() {
    int a,b,c; cin>>a>>b>>c;

    if(a > b) {
        int t = a;
        a = b;
        b = t;
    }
    if(a > c) {
        int t = a;
        a = c;
        c = t;
    }
    if(b > c) {
        int t = b;
        b = c;
        c = t;
    }
    // a<=b <= c
    if(a + b > c) {
        if(a*a +b*b == c*c) cout<<"zhijiao";
        if(a*a +b*b < c*c) cout<<"dunjiao";
        if(a*a +b*b > c*c) cout<<"ruijiao";
    } else cout<<"no";
    return 0;
}

P15闰年判断

#include<iostream>
using namespace std;

int main() {
	int y; cin>>y;
	if(y%400==0 || y%4==0 && y%100!=0){
		cout<<"yes";
	}else cout<<"no";
	return 0;
}

P16判断某年某月的天数

#include <iostream>
using namespace std;

/*
1   2   3   4   5     6   7   8   9    10    11  12
31 28  31  30   31   30  31   31  30    31   30  31

31 : 1  3  5  7 8 10 12
30 : 4  6  9  11

*/
int main() {
    int y,m, day=31; cin>>y>>m;
    if(m==4 || m==6 || m==9 || m==11){
        day = 30;
    }else if(m==2){
        if(y%400==0 || y%4==0 && y%100!=0) day=29;
        else day = 28;
    }
    cout<<day;
    return 0;
}

P17汉译英

#include<iostream>
using namespace std;

int main(){
	int n;cin>>n;
	if(1<=n&&n<=9){
		if(n==1) cout<<"one";
		if(n==2) cout<<"two";
		if(n==3) cout<<"three";
		if(n==4) cout<<"four";
		if(n==5) cout<<"five";
		if(n==6) cout<<"six";
		if(n==7) cout<<"seven";
		if(n==8) cout<<"eight";
		if(n==9) cout<<"nine";
	}else{
		cout<<"out";
	}
	return 0;
}

int main2(){
	int n; cin>>n;
	
	if(n==1) cout<<"one";
	else if(n==2) cout<<"two";
	else if(n==3) cout<<"three";
	else if(n==4) cout<<"four";
	else if(n==5) cout<<"five";
	else if(n==6) cout<<"six";
	else if(n==7) cout<<"seven";
	else if(n==8) cout<<"eight";
	else if(n==9) cout<<"nine";
	else cout<<"out";

	return 0;
}

P18交换两数

#include<iostream>
using namespace std;

int main(){
	int a,b; cin>>a>>b;
	if(a > b){
		int t = a;
		a = b;
		b = t;
	}
	cout<<a<<" "<<b;
	return 0;
}

P19苹果和虫子/Apples Prologue

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

int main(){
	int m,t,s; cin>>m>>t>>s;
	if( t!=0 ){
		m -= ceil(1.0*s/t);
		if( m < 0 ) m=0;
	}else m=0;
	
	cout<<m;
	return 0;
}

P20写评语

#include<iostream>
using namespace std;

int main(){
	int score; cin>>score;
	
	if(score < 60) cout<<"Fail";
	else if(score < 80) cout<<"Pass";
	else if(score < 90) cout<<"Good";
	else cout<<"Excellent";
	return 0;
}