【算法总结】基本算法

 1 #include<cstdio>
 2 #include<algorithm> 
 3 #include<cstring>
 4 #define LL long long
 5 using namespace std;
 6 const int N=1e5+10;
 7 int n,len,a[N];
 8 int read()
 9 {
10     int x=0,f=1;char c=getchar();
11     while(c<‘0‘||c>‘9‘){if(c==‘-‘)f=-1;c=getchar();}
12     while(c>=‘0‘&&c<=‘9‘){x=x*10+c-‘0‘;c=getchar();}
13     return x*f;
14 }
15 int main()
16 {
17     n=read();
18     for(int i=1;i<=n;i++)
19     {
20         a[i]=read();len=i;
21         while(len!=1)
22         {
23             if(a[len]<a[len/2])swap(a[len],a[len/2]);
24             else break;len>>=1;
25         }
26     }
27     for(int i=1;i<=n;i++)
28     {
29         printf("%d ",a[1]);
30         a[1]=a[n-i+1];len=1;
31         while(len*2<=n-i)
32         {
33             int next=len*2;
34             if(a[next]>a[next+1]&&next<n-i)next++;
35             if(a[len]<=a[next])break;
36             swap(a[len],a[next]);len=next;
37         }
38     }
39     return 0;
40 }

1 int main()
2 {
3     while(r-l>1e-6)
4     {
5         mid1=l+(r-l)/3;mid2=r-(r-l)/3;
6         if(calc(mid1)<calc(mid2))l=mid1;
7         else r=mid2;
8     }
9 }