一元多项式的乘法与加法运算（20 分）
1 | //初版18分， |
终结版 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129#include <iostream>
#include <vector>
#include<algorithm>
using namespace std;
typedef struct {
int zhishu;
int xishu;
}danxiang;
bool cmp(danxiang a,danxiang b)
{
return a.zhishu>b.zhishu;
}
int main()
{
vector<danxiang> a,b,jiafa,chengfa;
int n,zhishu,xishu;
cin>>n;
while(n--)
{
danxiang tmp;
cin>>tmp.xishu>>tmp.zhishu;
a.push_back(tmp);
}
cin>>n;
while(n--)
{
danxiang tmp2;
cin>>tmp2.xishu>>tmp2.zhishu;
b.push_back(tmp2);
}
//for(int i=0;i<a.size();i++)
// cout<<a[i].zhishu<<a[i].xishu;
//乘法
for(int i=0;i<a.size();i++)
{
for(int j=0;j<b.size();j++)
{
danxiang tmp3;
tmp3.xishu=a[i].xishu*b[j].xishu;
tmp3.zhishu=a[i].zhishu+b[j].zhishu;
chengfa.push_back(tmp3);
}
}
//排序+合并同类项
sort(chengfa.begin(),chengfa.end(),cmp);
int tmp;
if(chengfa.size()>1)
{
for(vector<danxiang>::iterator i=chengfa.begin()+1;i!=chengfa.end();i++)
{
if(i->zhishu==(i-1)->zhishu)
{
(i-1)->xishu+=i->xishu;
i->xishu=0;
}
}
}
int flag=0;
for(int i=0;i<chengfa.size();i++)
{
if(flag&&chengfa[i].xishu!=0) {
cout << " ";
}
if(chengfa[i].xishu!=0) {
cout << chengfa[i].xishu << " " << chengfa[i].zhishu;
flag = 1;
}
}
if(flag==0)
cout<<"0 0";
cout<<endl;
//加法
for(int i=0;i<a.size();i++)
jiafa.push_back(a[i]);
for(int i=0;i<b.size();i++)
jiafa.push_back(b[i]);
if(jiafa.size()>1)
{
for(vector<danxiang>::iterator i=jiafa.begin();i!=jiafa.end()-1;i++)
{
for(vector<danxiang>::iterator j=i+1;j!=jiafa.end();j++)
{
if(i->zhishu==j->zhishu)
{
i->xishu+=j->xishu;
j->xishu=0;
}
}
}
}
sort(jiafa.begin(),jiafa.end(),cmp);
flag=0;
for(int i=0;i<jiafa.size();i++)
{
if(flag&&jiafa[i].xishu!=0) {
cout<< " ";
}
if(jiafa[i].xishu!=0)
{
cout << jiafa[i].xishu << " " << jiafa[i].zhishu;
flag=1;
}
}
if(flag==0)
cout<<"0 0";
return 0;
}
可以通过下面的代码理解一下:
#include
int main()
{
vector<int> a;
for(int i=0;i<10;i++)
a.push_back(i);
/*
for(vector<int>::iterator i=a.begin();i!=a.end();i++)
cout<<"地址: "<<&i<<" "<<"数值: "<<*i<<endl;
*/
for(vector<int>::iterator i=a.begin();i!=a.end();i++)
{
cout<<"地址: "<<&i<<" "<<"数值: "<<*i<<endl;
a.erase(i);
cout<<"使用erase之后: "<<&i<<" "<<*i<<endl;
}
cout<<"删除之后的"<<endl;
for(vector<int>::iterator i=a.begin();i!=a.end();i++)
cout<<*i<<endl;
}ps：可以看到迭代器i的地址在一个循环中始终不变，所以说i作为一个迭代器和指针类似，但是并不是指针，可能是他的数据区才用来指向迭代数据的地址
