1002. A+B for Polynomials (25)

This time, you are supposed to find A+B where A and B are two polynomials.

Input

Each input file contains one test case. Each case occupies 2 lines, and each line contains the information of a polynomial: K N1 aN1 N2 aN2 … NK aNK, where K is the number of nonzero terms in the polynomial, Ni and aNi (i=1, 2, …, K) are the exponents and coefficients, respectively. It is given that 1 <= K <= 10，0 <= NK < … < N2 < N1 <=1000.

Output

For each test case you should output the sum of A and B in one line, with the same format as the input. Notice that there must be NO extra space at the end of each line. Please be accurate to 1 decimal place.

Sample Input

2 1 2.4 0 3.2

2 2 1.5 1 0.5

Sample Output

3 2 1.5 1 2.9 0 3.2

思路：一开始的思路是用链表解决。霹雳巴拉写了一百多行代码，递交，只通过两个测试点。。。仔细一看题目，最多就是1000项。。。可能。。。用数组实现更简单。。。如果在考场写链表的话，还是要一定的熟练度的。。。

#include<stdio.h>
#include<stdlib.h>

typedef struct Node *PtrToNode;
typedef PtrToNode Polynomial;
typedef PtrToNode Position;
struct Node {
int Exp;
float Coe;
Position Next;
};

Polynomial Read_Polynomial ( void );
Position Creat_a_PolynomialNode ( void );
Position Find_the_PolynomialLast ( Polynomial P );
Position Attach_to_Polynomial( Polynomial P, Position TmpCell );
Position Find_the_last( Polynomial P );
void Print_Polynomial ( Polynomial P );
Position Add_Polynomial ( Polynomial P1, Polynomial P2 );
int Count_Item ( Polynomial P );

int main ( void )
{
Polynomial P1 = NULL;
P1 = Read_Polynomial ( );

Polynomial P2 = NULL;
P2 = Read_Polynomial( );

Polynomial P3 = Add_Polynomial( P1, P2 );
int count = Count_Item( P3 );
printf("%d ", count );
Print_Polynomial( P3 );

return 0;
}

Polynomial Read_Polynomial ( )
{
int N = 0;
scanf("%d", &N );
Polynomial P = NULL;

while ( N-- ){
int temp_exponent = 0;
float temp_coefficient = 0;
scanf("%d", &temp_exponent );
scanf("%f", &temp_coefficient );
Position TmpCell = Creat_a_PolynomialNode ( );
TmpCell->Exp = temp_exponent;
TmpCell->Coe = temp_coefficient;
TmpCell->Next = NULL;
P = Attach_to_Polynomial ( P, TmpCell );
}
return P;
}

Position Creat_a_PolynomialNode ( void )
{
Position P = ( Position ) malloc ( sizeof ( struct Node ) );
return P;
}
Position Attach_to_Polynomial( Polynomial P, Position TmpCell )
{
Position last = P;
if ( last ){
last = Find_the_last( P );
last->Next = TmpCell;
}else {
P = TmpCell;
}

return P;
}
Position Find_the_last( Polynomial P )
{
Position last = P;
while ( last->Next ){
last = last->Next;
}
return last;
}
void Print_Polynomial ( Polynomial P )
{
Position Temp_P = P;
while ( Temp_P ){
if ( Temp_P->Next ){
printf("%d %.1f ",  Temp_P->Exp, Temp_P->Coe);
Temp_P = Temp_P->Next;
}else {
printf("%d %.1f",  Temp_P->Exp, Temp_P->Coe);
Temp_P = Temp_P->Next;
}

}
}

Position Add_Polynomial ( Polynomial P1, Polynomial P2 )
{
Polynomial P = NULL;

while( P1 && P2 ){
if ( P1->Exp  >  P2->Exp ){
Position temp = Creat_a_PolynomialNode();
temp->Exp = P1->Exp;
temp->Coe = P1->Coe;
temp->Next = NULL;
P = Attach_to_Polynomial(P, temp);
P1 = P1->Next;
}else if ( P1->Exp  ==  P2->Exp ){
Position temp = Creat_a_PolynomialNode();
temp->Exp = P1->Exp;
temp->Coe = P1->Coe;
temp->Next = NULL;
P = Attach_to_Polynomial(P, temp);
P1 = P1->Next;
P2 = P2->Next;
}else if ( P1->Exp < P2->Exp){
Position temp = Creat_a_PolynomialNode();
temp->Exp = P2->Exp;
temp->Coe = P2->Coe;
temp->Next = NULL;
P = Attach_to_Polynomial(P, temp);
P2 = P2->Next;
}
}
if ( P1 ){
Position last = Find_the_last( P );
last->Next = P1;
}
if ( P2 ){
Position last = Find_the_last( P );
last->Next = P2;
}
return P;
}

int Count_Item ( Polynomial P )
{
int count = 0;
Position Temp_P = P;

while ( Temp_P){
count++;
Temp_P = Temp_P->Next;
}

return count;
}

查看别人更加快捷的解法，果然用数组在时间上更加经济，空间上可能会浪费一些。

#include<stdio.h>
double coefficient[1001];
int main()
{
int i,count=0,n,index;
double temp;
scanf("%d",&n);
for(i=0;i<n;i++)
{
scanf("%d%lf",&index,&temp);
coefficient[index]+=temp;
}
scanf("%d",&n);
for(i=0;i<n;i++)
{
scanf("%d%lf",&index,&temp);
coefficient[index]+=temp;
}
for(i=1000;i>=0;i--)
{
if(coefficient[i]!=0)
{
count++;
index=i;
}
}
if(count>0)
{
printf("%d ",count);
for(i=1000;i>index;i--)
{
if(coefficient[i]!=0)
printf("%d %.1lf ",i,coefficient[i]);
}
printf("%d %.1lf",i,coefficient[i]);
}
else
printf("%d",count);

}