Luogushuati log -P1067 polynomial output

Title Description

One yuan n- n-degree polynomial expression as expressed available:

f(x)=a_nx^n+a_{n-1}x^{n-1}+\cdots +a_1x+a_0,a_n\ne 0f(x)=an​xn+an−1​xn−1+⋯+a1​x+a0​,an​​=0

Wherein, a_ix ^ i A i X i called i i-th order term, a_i A i  called i coefficients of the i-th term. Gives a univariate polynomial and the number of multipliers, the required output of the polynomial specified in the following format:

1. Is a polynomial argument X X, from left to right in descending frequency order polynomial is given.

2. Contains only the polynomial coefficients is not 0 0 entries.

3. If the polynomial the n- the n-order term coefficient is positive, then the polynomial is not the beginning of a "+" sign, if the polynomial the n- the n-order term coefficient is negative, the polynomial a "-" sign at the beginning.

For not the highest order terms to the "+" or "-" sign this connection with the previous item, respectively, this coefficient is positive or negative coefficient. Followed by a positive integer that represents the absolute value of this coefficient (if a higher than 0 the zero-order term, the absolute value of the coefficient . 1 1, the output is not necessary  . 1 1). If X X greater than the index . 1 1, the exponential portion immediately next to " X ^ B X B", wherein  B B is  X X index; if  X X's index . 1 1, the next immediately the exponent part with the form " X X"; if  X X index of 0 to 0, the coefficients can only output.

Polynomials, polynomial beginning, the end, without extra spaces.

Input Format

Enter the total of  2 2 lines

The first line . 1 an integer, n- n-, the number of univariate polynomial representation.

The second row has  n-1 + n- + 1 integers, the first of which I I denotes the integer n-1 + I- n- - I + coefficient of the linear term, between each two integers separated by a space.

Output Format

Total output  . 1 one line, the output of the polynomial by topic format.

Sample input and output

Input # 1copy

5 
100 -1 1 -3 0 10

Output # 1copy

100x^5-x^4+x^3-3x^2+10

Input # 2copy

3 
-50 0 0 1 

Output # 2copy

-50x^3+1 

Description / Tips

NOIP 2009 universal set of the first question

Data for 100%, 0 \ n-Le \ Le 100 0 ≤ n- ≤ . 1 0 0, -100 \ Le - . 1 0 0 ≤ coefficient \ 100 Le ≤ . 1 0 0

 

Problem solving process:

The subject is not difficult, just pay attention to some pit:

1. Several current coefficient is 0 when a nonzero coefficient note the absence of a positive number

2. When the coefficient is time 1or-1 does not require a digital output, however! ! The last digit is a 1 or -1 when the output is needed

3. coefficient than the first non-zero coefficient to pay attention to the issue in front of the

Generally these pits, finished after his own re-test a few samples, will be able to pass basic

code show as below:

. 1 #include <bits / STDC ++ H.>
 2  the using  namespace STD;
 . 3  
. 4  const  int MAXN = 10005 ;
 . 5 typedef Long  Long LL;
 . 6  
. 7  int A, n-;
 . 8  int NUM [MAXN];
 . 9  
10  // here x the output presented separately to facilitate opening below the writing 
. 11  void Print ( int n-)
 12 is  {
 13 is      IF (n-== 0 )
 14          return ;
 15      IF (n-> . 1 )
 16         cout<<"x^"<<n;
17     else
18         cout<<"x";
19     return;
20 }
21 
22 
23 int main()
24 {
25     while(cin>>n)
26     {
27         int k=n;
28         bool flag=true;
29         for(int i=0;i<=n;++i)
30         {
31             cin>>a;
32             if(a==0)
33             {
34                 k--;
35                 continue;
36             }
37             if(flag)
38             {
39                 if(a==1)
40                     print(k);
41                 else if(a==-1)
42                 {
43                     cout<<"-";
44                     print(k);
45                 }
46                 else
47                 {
48                     cout<<a;
49                     print(k);
50                 }
51                 flag=false;
52             }
53             else
54             {
55                 if(a==1)
56                 {
57                     cout<<"+";
58                     if(k!=0)
59                         print(k);
60                     else
61                           cout<<1;
62                 }
63                 else if(a==-1)
64                 {
65                     cout<<"-";
66                     if(k!=0)
67                         print(k);
68                     else
69                           cout<<1;
70                 }
71                 else if(a>0)
72                 {
73                     cout<<"+"<<a;
74                     print(k);
75                 }
76                 else
77                 {
78                     cout<<a;
79                     print(k);
80                 }
81             }
82             k--;
83         }
84         cout<<endl;
85     }
86     return 0;
87 }