题意:给定你大小未知的n个数,你允许有不超过一万次的询问,每次询问两个数,第i个数是否比第j个数小?然后后台会返回给你一个结果YES或者NO(即一行输入),
然后经过多次询问后,你需要给出一个正确的原未知序列的升序排列。
析:当时是真没看懂题意是啥意思,然后就放过了,如果看懂了,并不是很难么,这不就是一个排序么,你可以问后台要数据,然后你决定怎么排序,
我们只要处理这个排序就好,但是不能用sort进行排序,因为这个的复杂度并总不是nlogn,如果是极端数据就卡不过了,也就是说可能会超过询问10000次,
要么我们自己写个快排要么用stabble_sort,这个排序函数来解决。
代码如下:
#pragma comment(linker, "/STACK:1024000000,1024000000") #include <cstdio> #include <string> #include <cstdlib> #include <cmath> #include <iostream> #include <cstring> #include <set> #include <queue> #include <algorithm> #include <vector> #include <map> #include <cctype> #include <cmath> #include <stack> #define freopenr freopen("in.txt", "r", stdin) #define freopenw freopen("out.txt", "w", stdout) using namespace std; typedef long long LL; typedef pair<int, int> P; const int INF = 0x3f3f3f3f; const double inf = 0x3f3f3f3f3f3f; const double PI = acos(-1.0); const double eps = 1e-8; const int maxn = 1e3 + 5; const int mod = 1e9 + 7; const int dr[] = {-1, 0, 1, 0}; const int dc[] = {0, 1, 0, -1}; const char *de[] = {"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"}; int n, m; const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; const int monn[] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; inline int Min(int a, int b){ return a < b ? a : b; } inline int Max(int a, int b){ return a > b ? a : b; } inline LL Min(LL a, LL b){ return a < b ? a : b; } inline LL Max(LL a, LL b){ return a > b ? a : b; } inline bool is_in(int r, int c){ return r >= 0 && r < n && c >= 0 && c < m; } int a[maxn]; string s; bool cmp(int a, int b){ cout << "1 " << a << " " << b << endl; cin >> s; return s[0] == 'Y'; } int main(){ cout.flush(); cin >> n; for(int i = 0; i < n; ++i) a[i] = i+1; stable_sort(a, a+n, cmp); cout << "0"; for(int i = 0; i < n; ++i) cout << " " << a[i]; cout << endl; return 0; }