习题8-6(uva-1611)

1.冒泡,依次选1-n
2.先把当前选择的数 放在前半部分(保证下一步能把当前数放在前面)
每个数最多2个操作

#include <iostream>
#include <istream>
#include <sstream>
#include <vector>
#include <stack>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <cstring>
#include <unordered_map>
#include <unordered_set>
#include <algorithm>
#include <numeric>
#include <chrono>
#include <ctime>
#include <cmath>
#include <cctype>
#include <string>
#include <cstdio>
#include <iomanip>


#include <thread>
#include <mutex>
#include <condition_variable>
#include <functional>
#include <iterator>
using namespace std;
const int maxn = 1e5 + 7;
int input[maxn],n,ans[maxn<<1],cnt;

void SwapArr(int first, int last) {
	if (first >= last) return;
	int* fp = input + first, * lp = input + (first + last >> 1) + 1,*over = lp;
	while (fp != over) {
		swap(*fp++, *lp++);
	}
	ans[cnt++] = first;
	ans[cnt++] = last;
}
void GetResult(int first, int last) {
	while (first <= last && input[first] == first) ++first;
	if (first > last) return;

	int index = find(input + first, input + last + 1,first) - input,len = index - first;

	if (index > (first + last >> 1)) {
		int tcnt = index - first + 1,tFirst = first;
		if (tcnt & 1) tFirst++;
		SwapArr(tFirst, index);

		len = find(input + first, input + last + 1, first) - input;
		len -= first;
	}
	SwapArr(first, first + len * 2 - 1);

	GetResult(first + 1, last);
}

int main()
{
	int t;
	cin >> t;
	while (t--) {
		cin >> n, cnt = 0;
		for (int i = 1; i <= n; i++)cin >> input[i];
		
		GetResult(1, n);
		cout << (cnt >> 1) << endl;
		for (int i = 0; i < cnt; i+=2) {
			cout << ans[i] << " " << ans[i + 1] << endl;
		}
	}
	return 0;
}

标签：index,last,int,1611,input,uva,习题,include,first
来源： https://blog.csdn.net/seanbill/article/details/116857186