Rokua P1459 of three values sorting a three-valued Sequence

P1459 of three values sorting a three-valued SequenceTitle Description

Sorting is a very frequent computational task. Now consider sorting problems with up to three values. A practical example is when we give a winner of a competition a sort of gold and silver medal. The possible values in this task are only three and 3. We put him in ascending order by means of an exchange.

Write a program that calculates the minimum number of exchanges required for a given sequence of one-and-a-line numbers, in ascending order

input/output formatInput Format:

First line:

Number of medals N (1 <= n <= 1000)

Line 2nd to section n+1:

Each line is a number that represents the medal. Total n rows. (1.. 3)

output Format:

A total of one row, a number. Represents the minimum number of exchanges required to rank in ascending order.

input/Output sampleInput Sample # #: Copy

9221333231

Output Example # #: Replication

4

Description

Usaco 2.1

Translation from Nocow

Idea: Greed.

#include <map>#include<cstdio>#include<cstring>#include<iostream>#include<algorithm>using namespacestd;intN,ans;inta[10000];intnum[10000],pos[10000];intMain () {scanf ("%d",&N);  for(intI=1; i<=n;i++) scanf ("%d", &num[i]), pos[num[i]]++;  for(intI=1; i<=pos[1]+pos[2];i++){        if(num[i]==3) a[3]++; Else if(num[i]==2&&i<=pos[1]) a[1]++; Else if(num[i]==1&&i>pos[1]) a[2]++; } cout<<a[3]+ (a[1]>a[2]?a[1]:a[2]) <<Endl;}

Rokua P1459 of three values sorting a three-valued Sequence