一群人坐在一排，编号从1到n。每个人都被问到相同的问题，“你们国家中有多少人?”
人们提供的答案可能不正确。同一国家的人民总是坐在一起。如果所有答案均正确，请确定其他国家/地区的数量，否则请打印“无效答案”。
例子：
Input : ans[] = {1, 3, 2, 2}
Output : Invalid Answer
The second person says there are 3
people from his country however
the person sitting next to him says
there are 2 people. Hence this is
an invalid answer.
Input : ans[] = {1, 1, 2, 2, 4, 4,
4, 4}
Output : 4
There are 1 person each representing
two distinct countries. In the next
one there are two people and in the
fourth one there are 4 people from
the same country.
资料来源：ThoughtWorks应用资格考试
这是一个可以在线性时间内解决的基本问题。我们将使用一个变量curr_size，它告诉我们正在考虑的当前国家/地区的大小。无论人数多少，下一个“人数”人数都应给出相同的答案，以便形成有效的群体。如果有人给出了不同的答案，或者可用人数少于该人数，则答案为无效。下面是想法的实现：
C++
// CPP program to count no of distinct
// countries from a given group of people
#include
using namespace std;
void countCountries(int ans[], int N)
{
int total_countries = 0, i = 0;
bool invalid = false;
while (i < N) {
int curr_size = ans[i];
// Answer is valid if adjacent sitting
// num people give same answer
int num = ans[i];
while (num > 0) {
// someone gives different answer
if (ans[i] != curr_size) {
cout << "Invalid Answer\n";
return;
}
else
num--;
// check next person
i++;
}
// one valid country group has
// been found
total_countries++;
}
cout << "There are " << total_countries
<< " distinct companies in the group.\n";
}
// driver program to test above function
int main()
{
int ans[] = { 1, 1, 2, 2, 4, 4, 4, 4 };
int n = sizeof(ans) / sizeof(ans[0]);
countCountries(ans, n);
return 0;
} Java
// Java program to count no of distinct
// countries from a given group of people
class Country
{
public static void countCountries(int ans[],
int N)
{
int total_countries = 0, i = 0;
boolean invalid = false;
while (i < N) {
int curr_size = ans[i];
// Answer is valid if adjacent sitting
// num people give same answer
int num = ans[i];
while (num > 0) {
// someone gives different answer
if (ans[i] != curr_size) {
System.out.print( "Invalid Answer\n" );
return;
}
else
num--;
// check next person
i++;
}
// one valid country group has
// been found
total_countries++;
}
System.out.print( "There are " + total_countries +
" distinct companies in the group.\n" );
}
// driver code
public static void main(String[] args)
{
int ans[] = { 1, 1, 2, 2, 4, 4, 4, 4 };
int n = 8;
countCountries(ans, n);
}
}
// This code is contributed by rishabh_jainPython3
# Python3 program to count no of distinct
# countries from a given group of people
def countCountries(ans, N):
total_countries = 0
i = 0
invalid = 0
while (i < N) :
curr_size = ans[i]
# Answer is valid if adjacent sitting
# num people give same answer
num = ans[i]
while (num > 0) :
# someone gives different answer
if (ans[i] != curr_size) :
print("Invalid Answer")
return;
else:
num = num - 1
# check next person
i = i + 1
# one valid country group has
# been found
total_countries = total_countries + 1;
print ("There are ", total_countries,
" distinct companies in the group.")
# Driven code
ans = [ 1, 1, 2, 2, 4, 4, 4, 4 ];
n = len(ans);
countCountries(ans, n);
# This code is contributed by "rishabh_jain".C#
// C# program to count no. of distinct
// countries from a given group of people
using System;
class Country {
// function to count no. of distinct
// countries from a given group of people
public static void countCountries(int []ans,
int N)
{
int total_countries = 0, i = 0;
while (i < N) {
int curr_size = ans[i];
// Answer is valid if adjacent sitting
// num people give same answer
int num = ans[i];
while (num > 0) {
// someone gives different answer
if (ans[i] != curr_size) {
Console.Write( "Invalid Answer\n" );
return;
}
else
num--;
// check next person
i++;
}
// one valid country group
// has been found
total_countries++;
}
Console.Write("There are " + total_countries +
" distinct companies in the group.\n" );
}
// Driver Code
public static void Main()
{
int []ans = { 1, 1, 2, 2, 4, 4, 4, 4 };
int n = 8;
countCountries(ans, n);
}
}
// This code is contributed by nitin mittalPHP
0)
{
// someone gives different
// answer
if ($ans[$i] != $curr_size)
{
echo"Invalid Answer\n";
return;
}
else
$num--;
// check next person
$i++;
}
// one valid country group has
// been found
$total_countries++;
}
echo "There are " , $total_countries
, " distinct companies in the group.\n";
}
// Driver Code
$ans = array(1, 1, 2, 2, 4, 4, 4, 4 );
$n = sizeof($ans);
countCountries($ans, $n);
// This code is contributed by nitin mittal.
?>输出：
There are 4 distinct companies in the group.