APCS程式檢測 -實作題1051029 第3題 定時K彈

APCS程式檢測 -實作題1051029 第3題 定時K彈

本題會使用到 C++ 的 STL vector，如果不熟悉的話可以來這裡看看
https://husking-studio.com/cpp-stl-vector/

找 vecPlayer 裡找爆炸玩家

程式碼

//找會爆炸的索引值
//nVecSize - STL vector 裡的資料總數
//nStartIndex - 從哪個玩家開始，注意這是索引值(index)，不是玩家編號
//nStep - 向下找幾個
int GetExplodeIndex(int nVecSize, int nStartIndex, int nStep)
{
	int nExplodeIndex = nStartIndex;
	for (int i = 0; i < (nStep-1); i++)
	{
		nExplodeIndex = nExplodeIndex + 1;
		if (nExplodeIndex >= nVecSize)		//找到最後，再從頭開始
			nExplodeIndex = 0;
	}
	return nExplodeIndex;
}

完整程式碼

#include <iostream>
#include <sstream>
#include <string>
#include <vector>
using namespace std;

int GetExplodeIndex(int nVecSize, int nStartIndex, int nStep);
vector<int>::iterator GetVectorItByIndex(vector<int>* pVector, int nIndex);

int main()
{
	int N = 0;
	int M = 0;
	int K = 0;

	//處理輸入
	string strInput;
	getline(cin, strInput);
	stringstream delim(strInput);
	string pch;

	getline(delim, pch, ' ');
	N = stoi(pch);

	getline(delim, pch, ' ');
	M = stoi(pch);

	getline(delim, pch, ' ');
	K = stoi(pch);

	//設定玩家 vector
	vector<int> vecPlayer;
	for (int i = 0; i < N; i++)
		vecPlayer.push_back(i + 1);

	int nStartIndex = 0;	//開始的索引值
	int nExplodeIndex = 0;	//會爆炸的索引值
	int nLuckyIndex = 0;	//爆炸的下一個索引值
	vector<int>::iterator eraseIt;

	for (int i = 0; i < K; i++)
	{
		nExplodeIndex = GetExplodeIndex((int)vecPlayer.size(), nStartIndex, M);	//找會爆炸的索引值
		//cout << "Explode player:" << vecPlayer[nExplodeIndex] << endl;	//可以印出爆炸玩家
		eraseIt = GetVectorItByIndex(&vecPlayer, nExplodeIndex);	//找會爆炸的索引值的 it
		vecPlayer.erase(eraseIt);		//將會爆炸的索引值的 it 從玩家 vector 中刪除

		nStartIndex = nExplodeIndex;	//下一輪從爆炸這裡開始

		nLuckyIndex = nExplodeIndex + 1;	//爆炸的下一個索引值，就是幸運玩家的索引值
		if (nLuckyIndex >= (int)vecPlayer.size())
			nLuckyIndex = 0;
	}

	cout << vecPlayer[nLuckyIndex] << endl;

	system("pause");
	return 0;
}
vector<int>::iterator GetVectorItByIndex(vector<int>* pVector, int nIndex)
{
	if (nIndex < 0 || nIndex >= (int)pVector->size())
		return pVector->end();

	vector<int>::iterator it;
	it = pVector->begin();
	for (int i = 0; i < nIndex; i++)
		it++;

	return it;
}
int GetExplodeIndex(int nVecSize, int nStartIndex, int nStep)
{
	int nExplodeIndex = nStartIndex;
	for (int i = 0; i < (nStep - 1); i++)
	{
		nExplodeIndex = nExplodeIndex + 1;
		if (nExplodeIndex >= nVecSize)
			nExplodeIndex = 0;
	}
	return nExplodeIndex;
}