A1088.Rational Arithmetic

题意

模拟分数的四则运算

思路分析

模拟，在输出过程中，若分子>分母，需要分离出整数部分与分数部分，并且如果项为负数需要带上()

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

struct fraction{
	ll up;	//分子 
	ll down;		//分母 
}a,b,result;

ll gcd(ll a,ll b){
	if(b == 0) return a;
	else return gcd(b,a%b);	
}

fraction simply(fraction a){			//对分子分母进行约分 
	if(a.down < 0) {			//如果输入分母是负数,统一为分子带符号，分母不带符号 
		a.up = -a.up;
		a.down = - a.down;
	}
	int GCD = gcd(abs(a.up),abs(a.down));
	a.up /= GCD;
	a.down /= GCD;
	return a;
}

void showResult(fraction a){
	a = simply(a);			//对a化简 	
	if(a.up < 0) printf("(");			//如果是负数 
	if(a.down == 1) printf("%lld",a.up);			//如果分母为1 
	else if(a.up == 0) printf("0");				//如果分子为0 
	else if(abs(a.up) > abs(a.down))			//如果分子>分母，需要输出整数部分 
		printf("%lld %lld/%lld",a.up/a.down,abs(a.up) % a.down,a.down);
	else if(abs(a.up) == abs(a.down)) printf("%d",a.up/a.down);			//分子=分母 
	else 
		printf("%lld/%lld",a.up,a.down);			//分子<分母 
	if(a.up < 0) printf(")");
}

fraction Sum(fraction a,fraction b){
	result.up = a.up * b.down + a.down * b.up;
	result.down = a.down * b.down;
	return simply(result);
}

fraction Mul(fraction a,fraction b) {
	result.up = a.up * b.up;
	result.down = a.down * b.down;
	return simply(result);
}

fraction Del(fraction a,fraction b) {
	result.up = a.up * b.down - a.down * b.up;
	result.down = a.down * b.down;
	return simply(result);
}

fraction div(fraction a,fraction b) {
	result.up = a.up * b.down;
	result.down = a.down * b.up;
	return simply(result);
}

int main(void){
	scanf("%lld/%lld %lld/%lld",&a.up,&a.down,&b.up,&b.down);
	//加法 
	showResult(a);
	printf(" + ");
	showResult(b);
	printf(" = ");
	showResult(Sum(a,b));
	cout<<endl;
	
	//减法
	showResult(a);
	printf(" - ");
	showResult(b);
	printf(" = ");
	showResult(Del(a,b));	
	cout<<endl;
	
	//乘法
	showResult(a);
	printf(" * ");
	showResult(b);
	printf(" = ");
	showResult(Mul(a,b)); 
	cout<<endl;
	//除法
	showResult(a);
	printf(" / ");
	showResult(b);
	printf(" = ");
	if(b.up == 0) cout<<"Inf";
	else showResult(div(a,b)); 
	return 0;
}

总结

PAT 第一道题20分就这么难，这还考个球啊。屎山模拟，恶心到吐血，考虑细节较多