hdu 2034 - 集合操作

题意：集合A,B，计算集合差A-B（求只在集合A内的数）

解法：

选用STL内的集合set

1.建立set

   1:  #include<set>

   2:   

   3:  set<int> se;

.csharpcode, .csharpcode pre
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font-family: consolas, "Courier New", courier, monospace;
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.csharpcode pre { margin: 0em; }
.csharpcode .rem { color: #008000; }
.csharpcode .kwrd { color: #0000ff; }
.csharpcode .str { color: #006080; }
.csharpcode .op { color: #0000c0; }
.csharpcode .preproc { color: #cc6633; }
.csharpcode .asp { background-color: #ffff00; }
.csharpcode .html { color: #800000; }
.csharpcode .attr { color: #ff0000; }
.csharpcode .alt
{
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width: 100%;
margin: 0em;
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.csharpcode .lnum { color: #606060; }

2.关于集合的遍历，固定的格式：

用容器的iterator访问所有数据。

   1:  for(set<int>::iterator it=a.begin();it!=a.end();it++){

   2:      //TO DO

   3:  }

.csharpcode, .csharpcode pre
{
font-size: small;
color: black;
font-family: consolas, "Courier New", courier, monospace;
background-color: #ffffff;
/*white-space: pre;*/
}
.csharpcode pre { margin: 0em; }
.csharpcode .rem { color: #008000; }
.csharpcode .kwrd { color: #0000ff; }
.csharpcode .str { color: #006080; }
.csharpcode .op { color: #0000c0; }
.csharpcode .preproc { color: #cc6633; }
.csharpcode .asp { background-color: #ffff00; }
.csharpcode .html { color: #800000; }
.csharpcode .attr { color: #ff0000; }
.csharpcode .alt
{
background-color: #f4f4f4;
width: 100%;
margin: 0em;
}
.csharpcode .lnum { color: #606060; }

.csharpcode, .csharpcode pre
{
font-size: small;
color: black;
font-family: consolas, "Courier New", courier, monospace;
background-color: #ffffff;
/*white-space: pre;*/
}
.csharpcode pre { margin: 0em; }
.csharpcode .rem { color: #008000; }
.csharpcode .kwrd { color: #0000ff; }
.csharpcode .str { color: #006080; }
.csharpcode .op { color: #0000c0; }
.csharpcode .preproc { color: #cc6633; }
.csharpcode .asp { background-color: #ffff00; }
.csharpcode .html { color: #800000; }
.csharpcode .attr { color: #ff0000; }
.csharpcode .alt
{
background-color: #f4f4f4;
width: 100%;
margin: 0em;
}
.csharpcode .lnum { color: #606060; }

3.相应的用*it访问set内的数据

4.set内的数据会自动排序，从小到大的顺序。

5.关于find()操作：

如果找不到，会返回set.end()

附上我的代码:

   1:  #include<iostream>

   2:  #include<cstdio>

   3:  #include<cstdlib>

   4:  #include<string>

   5:  #include<string.h>

   6:  #include<set>

   7:  using namespace std;

   8:  int main(){

   9:      int n,m,tmp;

  10:      while(scanf("%d %d",&n,&m)!=EOF&&(n||m)){

  11:          set<int> a,b;

  12:          while(n--){

  13:              scanf("%d",&tmp);

  14:              a.insert(tmp);

  15:          }

  16:          while(m--){

  17:              scanf("%d",&tmp);

  18:              b.insert(tmp);

  19:          }

  20:          int cnt=0;

  21:          for(set<int>::iterator it=a.begin();it!=a.end();it++){

  22:              if(b.find(*it)==b.end()){

  23:                  printf("%d ",*it);

  24:                  cnt++;

  25:              }

  26:          }

  27:          if(cnt==0)printf("NULL");

  28:          printf("\n");

  29:      }

  30:  }

  31:      

.csharpcode, .csharpcode pre
{
font-size: small;
color: black;
font-family: consolas, "Courier New", courier, monospace;
background-color: #ffffff;
/*white-space: pre;*/
}
.csharpcode pre { margin: 0em; }
.csharpcode .rem { color: #008000; }
.csharpcode .kwrd { color: #0000ff; }
.csharpcode .str { color: #006080; }
.csharpcode .op { color: #0000c0; }
.csharpcode .preproc { color: #cc6633; }
.csharpcode .asp { background-color: #ffff00; }
.csharpcode .html { color: #800000; }
.csharpcode .attr { color: #ff0000; }
.csharpcode .alt
{
background-color: #f4f4f4;
width: 100%;
margin: 0em;
}
.csharpcode .lnum { color: #606060; }