(数组的应用三:多项式的表示与处理4.3.1)POJ 1555 Polynomial Showdown(多项式的输出)

/*
* poj_1555.cpp
*
*  Created on: 2013年10月25日
*      Author: Administrator
*/

#include <iostream>
#include <cstdio>
#include <cmath>
#include <algorithm>

using namespace std;

const int n = 9;//指数由8~0是有9个数字的
int main(){
int a
;

while(scanf("%d",&a[0])!=EOF){//不要漏了EOF，否则会OLE。。要是用多种测试用例尽量将程序写成能处理多个测试样例的程序...否则就算逻辑正确也很可能WA
int i;
for(i = 1 ; i < n ; ++i){
scanf("%d",&a[i]);
}

bool first = true;

for(i = 0 ; i < n ; ++i){
if(a[i]){//按照指数由高到低输出非0项
if(first){//处理首项
if(a[i] == -1 && i < n - 1){
cout<<"-";
}else if(a[i] != 1 || i == n - 1){
cout<<a[i];
}

if(i == n - 2){
cout<<"x";
}else if(i < n - 1){
cout<<"x^"<<n - i - 1;
}

first = false;
}else{
cout<<" "<<(a[i] < 0 ? "-":"+")<<" ";

if(abs(a[i]) != 1 || i == n - 1){
cout<<abs(a[i]);
}

if(i == n-2){
cout<<"x";
}else if(i < n - 1){
cout<<"x^"<<n-i-1;
}

}
}
}

if(first){//如所有系数都为0,则输出0
cout<<"0";
}

cout<<endl;
}

return 0;
}