题意:查找只被竞价一次的价格中的最小值。
set用法:
http://www.cnblogs.com/BeyondAnyTime/archive/2012/08/13/2636375.html
#include <iostream>
#include <string>
#include <map>
#include <set>
#include <stdio.h>
using namespace std;
int main()
{
set<int> myset;
map<int,int> mymap;
char c;
int T,n,x;
scanf("%d",&T);
while(T--)
{
myset.clear();
mymap.clear();
scanf("%d",&n);
for(int i=0; i<n; i++)
{
scanf(" %c",&c);//空格忽略\n
if(c=='b')
{
scanf("%d",&x);
myset.insert(x);
mymap[x]++;
if(mymap[x]>1)
myset.erase(x);
}
else if(c=='c')
{
scanf("%d",&x);
mymap[x]--;
if(mymap[x]==1)
myset.insert(x);
else if(mymap[x]==0)
myset.erase(x);
}
else
{
if(!myset.empty())
printf("%d\n",*myset.begin());
else
printf("none\n");
}
}
}
return 0;
}