公式法循環
class Solution {
public:
int LastRemaining_Solution(int n, int m)
{
if(n<1 || m<1)
return -1;
int s=0;
for(int i=2;i<=n;i++)
{
s=(s+m)%i;
}
return s;
}
};
公式法遞歸
class Solution {
public:
int LastRemaining_Solution(int n, int m)
{
if(n<1 || m<1)
return -1;
if(n==1) return 0;
else return (LastRemaining_Solution(n-1,m)+m)%n;
}
};
鏈表法
class Solution {
public:
int LastRemaining_Solution(int n, int m)
{
if( n<1 || m <1 )//判斷邊界條件
return -1;
list<int> number;
for(int i=0;i<n;i++)//初始化鏈表
{
number.push_back(i);
}
list<int>::iterator current = number.begin();
while(number.size()>1)
{
for(int i=1;i<m;i++)//找到第m個結點，記住是循環m-1次而不是m次
{
current++;
if(current == number.end())
current = number.begin();
}
list<int>::iterator next = ++current;//保存刪除后的起始結點
if(next == number.end())
next = number.begin();
current--;
number.erase(current);
current = next;
}
return *current;
}
};
