cses 5

Author: thecodingwizard

README.md

@@ -548,5 +548,6 @@ Solutions to [CSES Problem Set](https://cses.fi/problemset/).
 | Missing Number | Basic Arrays |
 | Repetitions | Maximum length substring with same characters |
 | Increasing Array | Greedy |
+| Permutations | Ad Hoc, Construction |
 
 [Solutions Folder](cses)

cses/5 - Permutations.cpp

@@ -0,0 +1,93 @@
+#include <iostream>
+#include <string>
+#include <utility>
+#include <sstream>
+#include <algorithm>
+#include <stack>
+#include <vector>
+#include <queue>
+#include <map>
+#include <set>
+#include <bitset>
+#include <cmath>
+#include <cstring>
+#include <iomanip>
+#include <fstream>
+#include <cassert>
+#include <unordered_set>
+#include <ctime>
+#include <list>
+
+using namespace std;
+
+template<class T> using min_heap = priority_queue<T, vector<T>, greater<T>>;
+
+#define FOR(i, a, b) for (int i=a; i<(b); i++)
+#define F0R(i, a) for (int i=0; i<(a); i++)
+#define F0R1(i, a) for (int i=1; i<=(a); i++)
+#define FORd(i, a, b) for (int i = (b)-1; i >= a; i--)
+#define F0Rd(i, a) for (int i = (a)-1; i >= 0; i--)
+#define F0Rd1(i, a) for (int i=a; i>0; i--)
+#define SORT(vec) sort(vec.begin(), vec.end())
+#define MIN(a, b) a = min(a, b)
+#define MAX(a, b) a = max(a, b)
+
+#define INF 1000000010
+#define LL_INF 4500000000000000000
+#define LSOne(S) (S & (-S))
+#define EPS 1e-9
+#define pA first
+#define pB second
+#define mp make_pair
+#define pb push_back
+#define PI acos(-1.0)
+#define ll long long
+#define MOD (int)(2e+9+11)
+#define SET(vec, val, size) for (int i = 0; i < size; i++) vec[i] = val;
+#define SET2D(arr, val, dim1, dim2) F0R(i, dim1) F0R(j, dim2) arr[i][j] = val;
+#define SET3D(arr, val, dim1, dim2, dim3) F0R(i, dim1) F0R(j, dim2) F0R(k, dim3) arr[i][j][k] = val;
+#define SET4D(arr, val, dim1, dim2, dim3, dim4) F0R(i, dim1) F0R(j, dim2) F0R(k, dim3) F0R(l, dim4) arr[i][j][k][l] = val;
+#define READGRID(arr, dim) F0R(i, dim) F0R(j, dim) cin >> arr[i][j];
+#define all(x) (x).begin(), (x).end()
+
+typedef pair<int, int> ii;
+typedef pair<int, ii> iii;
+typedef pair<ll, ll> pll;
+typedef vector<int> vi;
+typedef vector<ii> vii;
+typedef vector<iii> viii;
+typedef vector<ll> vl;
+
+void setupIO(const string &PROB) {
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+    ifstream infile(PROB + ".in");
+    if (infile.good()) {
+        freopen((PROB + ".in").c_str(), "r", stdin);
+        freopen((PROB + ".out").c_str(), "w", stdout);
+    }
+}
+
+/* ============================ */
+
+int main() {
+    int n; cin >> n;
+    if (n == 1) cout << 1 << endl;
+    else if (n < 4) cout << "NO SOLUTION" << endl;
+    else {
+        vi toPrint;
+        F0R1(i, n) {
+            if (i & 1) continue;
+            toPrint.pb(i);
+        }
+        F0R1(i, n) {
+            if (!(i & 1)) continue;
+            toPrint.pb(i);
+        }
+        cout << toPrint[0];
+        FOR(i, 1, toPrint.size()) cout << " " << toPrint[i];
+        cout << endl;
+    }
+
+    return 0;
+}

main.cpp

@@ -1,9 +1,3 @@
-/*
-ID: nathan.18
-TASK: hidden
-LANG: C++
-*/
-
 #include <iostream>
 #include <string>
 #include <utility>
@@ -77,43 +71,23 @@ void setupIO(const string &PROB) {
 /* ============================ */
 
 int main() {
-    setupIO("hidden");
-
     int n; cin >> n;
-    char A[n]; F0R(i, n) cin >> A[i];
-
-    vi alive;
-    F0R(i, n) alive.pb(i);
-    bool ignore[n]; SET(ignore, false, n);
-
-    int ct = 0;
-    int aliveLeft = n;
-    while (alive.size() != 1) {
-        char best = '{';
-        vi keep;
-        for (int x : alive) {
-            if (ignore[x]) continue;
-
-            if (A[(x + ct) % n] < best) {
-                best = A[(x + ct) % n];
-                keep.clear();
-                keep.pb(x);
-            } else if (A[(x + ct) % n] == best) {
-                keep.pb(x);
-            }
+    if (n == 1) cout << 1 << endl;
+    else if (n < 4) cout << "NO SOLUTION" << endl;
+    else {
+        vi toPrint;
+        F0R1(i, n) {
+            if (i & 1) continue;
+            toPrint.pb(i);
         }
-        ct++;
-        for (int x : keep) {
-            if (aliveLeft == 1) break;
-            if (!ignore[(x + ct) % n]) {
-                ignore[(x + ct) % n] = true;
-                aliveLeft--;
-            }
+        F0R1(i, n) {
+            if (!(i & 1)) continue;
+            toPrint.pb(i);
         }
-        alive = keep;
+        cout << toPrint[0];
+        FOR(i, 1, toPrint.size()) cout << " " << toPrint[i];
+        cout << endl;
     }
 
-    cout << alive[0] << endl;
-
     return 0;
-}
+}