【线性表】一元多项式相乘

  1 /* PRESET CODE BEGIN - NEVER TOUCH CODE BELOW */

  2

  3 #include <stdio.h>

  4 #include <stdlib.h>

  5

  6 typedef struct node

  7 {   int    coef, exp;           //coef：系数     exp：指数

  8     struct node  *next;         //下一项

  9 } NODE;

 10

 11 NODE* multiplication( NODE *, NODE * , NODE * );

 12 void input( NODE * );

 13 void output( NODE * );

 14

 15 int main()

 16 {   NODE * head1, * head2, * head3;

 17

 18     head1 = ( NODE * ) malloc( sizeof(NODE) );

 19     input( head1 );

 20

 21     head2 = ( NODE * ) malloc( sizeof(NODE) );

 22     input( head2 );

 23

 24     head3 = ( NODE * ) malloc( sizeof(NODE) );

 25     head3->next = NULL;

 26     head3 = multiplication( head1, head2, head3 );

 27     output( head3 );

 28

 29     return 0;

 30 }

 31 /* PRESET CODE END - NEVER TOUCH CODE ABOVE */

 32 void input( NODE * head )      //输入顺序：<   -   0~9   ,    >

 33 {   int flag, sign, sum, x;    //sign：系数符号     sum：项系数,指数

 34     char c;

 35

 36     NODE * p = head;

 37

 38     while ( (c=getchar()) !=‘\n‘ )

 39     {

 40         if ( c == ‘<‘ )

 41         {    sum = 0;

 42              sign = 1;

 43              flag = 1;

 44         }

 45         else if ( c ==‘-‘ )

 46              sign = -1;

 47         else if( c >=‘0‘&& c <=‘9‘ )

 48         {    sum = sum*10 + c - ‘0‘;

 49         }

 50         else if ( c == ‘,‘ )

 51         {    if ( flag == 1 )

 52              {    x = sign * sum;

 53                   sum = 0;

 54                   flag = 2;

 55                   sign = 1;

 56              }

 57         }

 58         else if ( c == ‘>‘ )

 59         {    p->next = ( NODE * ) malloc( sizeof(NODE) );

 60              p->next->coef = x;                            //项系数

 61              p->next->exp  = sign * sum;                //指数

 62              p = p->next;

 63              p->next = NULL;

 64              flag = 0;

 65         }

 66     }

 67 }

 68 void output( NODE * head )

 69 {

 70     while ( head->next != NULL )

 71     {   head = head->next;

 72         printf("<%d,%d>,", head->coef, head->exp );

 73     }

 74     printf("\n");

 75 }

 76 NODE* multiplication( NODE *h1, NODE *h2 , NODE *h3 )//不允许修改指针内容

 77 {

 78     NODE *head1, *head2, *head3,*head;//head临时头指针

 79     int max_exp = 0,count_exp = 0;

 80     head1 = h1;

 81     head2 = h2;

 82     head3 = h3;

 83     while(head1->next!=NULL){

 84         while(head2->next!=NULL){

 85             head3->next = (NODE *) malloc(sizeof(NODE));

 86             head3->next->coef = head1->next->coef*head2->next->coef;

 87             head3->next->exp = head1->next->exp+head2->next->exp;

 88             head2 = head2->next;

 89             head3 = head3->next;

 90             head3->next = NULL;

 91             if(head3->exp>max_exp)            //记录最大指数

 92                 max_exp = head3->exp;

 93         }

 94         head2 = h2;      //返回头指针

 95         head1 = head1->next;

 96     }

 97     //合并指数相同的多项式

 98     head = (NODE *)malloc(sizeof(NODE));

 99     head->next = (NODE*)malloc(sizeof(NODE));

100     head3 = h3;             //返回头指针

101     head1 = head;

102     for(count_exp = 0;count_exp<=max_exp;count_exp++){

103         head->next->coef = 0;

104         head->next->exp = count_exp;

105         while(head3->next!=NULL){

106             if(count_exp == head3->next->exp)

107                 head->next->coef += head3->next->coef;

108             head3 = head3->next;

109         }

110         //零多项式标志位

111         if(head->next->coef != 0){

112             head = head->next;

113             head->next = (NODE*)malloc(sizeof(NODE));

114         }

115         head3 = h3;             //返回头指针

116     }

117     head->next = NULL;

118     return head1;

119 }

120

121

122  

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