codechef problems

CC_KSUB.cpp

@@ -0,0 +1,25 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+int main()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+    int t; cin>>t;
+    while(t--){
+    	int n, k, g=0, kc=0; cin>>n>>k;
+    	int arr[n];
+    	for(int i=0; i<n; i++) cin>>arr[i], g=__gcd(g, arr[i]);
+    	int tmpgcd=arr[0];
+    	for(int i=1; i<n; i++){
+    		if(tmpgcd==g){
+    			kc++; tmpgcd=arr[i];
+    		}
+    		tmpgcd=__gcd(tmpgcd, arr[i]);
+    	}
+    	if(tmpgcd==g) kc++;
+    	if(kc>=k) cout<<"YES\n";
+    	else cout<<"NO\n";
+    }
+    return 0;
+}

appledivision.cpp

@@ -0,0 +1,29 @@
+#include <bits/stdc++.h>
+using namespace std;
+#define int long long
+
+int res = INT_MAX, sum=0;
+int cnt=0;
+void fun(vector<int>&arr, int i, int s)
+{
+	res=min(abs(sum-2*s), res);
+	if(i<0)
+	return;
+	fun(arr, i-1, s);
+	fun(arr, i-1, s+arr[i]);
+}
+
+signed main()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+    int n; cin>>n;
+    vector<int> arr(n);
+
+    for(int i=0; i<n; i++) cin>>arr[i], sum+=arr[i];
+
+    fun(arr, n-1, 0);
+
+    cout<<res;
+    return 0;
+}

cses_NumberSpiral.cpp

@@ -0,0 +1,27 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+#define int long long
+
+signed main()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+ 	int q; cin>>q;
+ 	while(q--){
+ 		int r, c; cin>>r>>c;
+ 		if(r==c){
+ 			cout<<(r-1)*(r-1)+r<<"\n";
+ 			continue;
+ 		}
+ 		int mx=max(r, c)-1;
+ 		mx*=mx;
+ 		if((max(r, c)&1 and max(r, c)==c) or (max(r, c)%2==0 and max(r, c)==r)){
+ 			cout<<mx+2*max(r,c)-min(r, c)<<"\n";	
+ 		}
+ 		else{
+ 			cout<<mx+min(r,c)<<"\n";
+ 		}
+ 	}   
+    return 0;
+}

cses_TwoKnights.cpp

@@ -0,0 +1,13 @@
+#include <bits/stdc++.h>
+using namespace std;
+#define int long long
+signed main()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+    int n; cin>>n;
+    for(int i=1; i<=n; i++){
+    	cout<<(i*i*(i*i-1))/2-4*(i-1)*(i-2)<<"\n";
+    }
+    return 0;
+}

cses_bitstrings.cpp

@@ -0,0 +1,19 @@
+#include <bits/stdc++.h>
+using namespace std;
+#define P 1000000007
+int pow(int a, int n){
+	if(n==0) return 1;
+	if(n==1) return a;
+	long long tmp = pow(a, n/2)%P;
+	if(n&1) return (((tmp*tmp)%P)*a)%P;
+	return (tmp*tmp)%P;
+}
+
+signed main()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+    int n; cin>>n;
+    cout<<pow(2, n);
+    return 0;
+}

cses_chessboardandqueens.cpp

@@ -0,0 +1,58 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+#define int long long
+
+bool canplace(int r, int c, vector<vector<char>> &arr){
+
+	if(arr[r][c]!='.') return false;
+
+	for(int i=r; i>=0; i--)
+	if(arr[i][c]=='P') return false;
+
+	for(int i=c; i>=0; i--)
+	if(arr[r][i]=='P') return false;
+
+	for(int i=r, j=c; i>=0 && j>=0; i--, j--)
+	if(arr[i][j]=='P') return false;
+
+	for(int i=r, j=c; i>=0 && j<8; i--, j++)
+	if(arr[i][j]=='P') return false;
+	//cout<<r<<" "<<c<<"}";
+	return true;
+}
+
+void fun(vector<vector<char>> &grid, int r, int c, int&res, int cnt)
+{
+	if(cnt==8) res++;
+	if(cnt>8 or r>7 or c>7) return;
+	for(int i=r; i<8; i++){
+		for(int j=c; j<8; j++){
+			cout<<i<<" "<<j<<"}";
+			if(canplace(i, j, grid)){
+				char tmp='P';
+				swap(grid[i][j], tmp);
+				fun(grid, i+1, j+1, res, cnt+1);
+				swap(grid[i][j], tmp);
+			}
+			fun(grid, i+1, j+1, res, cnt);
+		}
+	}
+}
+
+signed main()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+    vector<vector<char>> grid(8,vector<char>(8));
+    for(int i=0; i<8; i++)
+    for(int j=0; j<8; j++)
+    cin>>grid[i][j];
+
+
+	int res=0;
+	fun(grid, 0, 0, res, 0);
+	cout<<res;
+
+    return 0;
+}

cses_graycode.cpp

@@ -0,0 +1,24 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+vector<string> fun(int n){
+	if(n<1) return {};
+	if(n==1) return {"0", "1"};
+	vector<string> res=fun(n-1), res2=res;
+	for(int i=0; i<res.size(); i++) res[i]= '0'+res[i];
+	for(int i=0; i<res2.size(); i++) res2[i]= '1'+res2[i];
+	for(int i=res2.size()-1; i>=0; i--) res.push_back(res2[i]);
+	return res;
+}
+
+int main()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+ 	int n; cin>>n;
+ 	vector<string> res = fun(n);
+ 	for(auto it : res){
+ 		cout << it <<"\n";
+ 	}   
+    return 0;
+}

cses_increasing_array.cpp

@@ -0,0 +1,19 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+template <typename T> T mmax(T a, T b){
+    return a>b?a:b;
+}
+int main()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+ 	long long n, sum=0, prev_mx; cin>>n>>prev_mx;
+ 	for(int i=0; i<n-1; i++){
+ 		long long curr; cin>>curr;
+ 		sum += mmax(prev_mx-curr, (long long int)0);
+ 		prev_mx = mmax(curr, prev_mx);
+ 	}
+ 	cout<<sum;
+    return 0;
+}

cses_palindromereorder.cpp

@@ -0,0 +1,29 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+int main()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+    string s; cin>>s;
+    unordered_map<char, int> mp;
+    for(auto it : s) mp[it]++;
+    int oc=0, cnt=0;
+    char c;
+	for(auto it : mp) if(it.second &1) oc++, c=it.first, cnt=it.second;
+	if(oc>1 or (s.size()%2==1 and oc!=1)) cout<<"NO SOLUTION";
+	else{
+		deque<char> q;
+        while(cnt-->0) q.push_front(c);
+        mp[c]=0;
+        for(auto it : mp){
+            while(mp[it.first]){
+                q.push_back(it.first);
+                q.push_front(it.first);
+                mp[it.first]-=2;
+            }
+        }
+        while(q.size()){ cout<<q.front(); q.pop_front();}
+	}
+    return 0;
+}

cses_permutations.cpp

@@ -0,0 +1,19 @@
+#include <bits/stdc++.h>
+using namespace std;
+#define int long long
+signed main()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+ 	int n; cin>>n;
+ 	if(n==1){
+ 		cout<<1; return 0;
+ 	}
+ 	if(n<4){
+ 		cout<<"NO SOLUTION";
+ 		return 0;
+ 	}
+	for(int i=2; i<=n; i+=2) cout<<i<<" ";
+	for(int i=1; i<=n; i+=2) cout<<i<<" ";
+    return 0;
+}

cses_trailingzeros.cpp

@@ -0,0 +1,12 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+int main()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+    long long n, ans=0; cin>>n;
+    for(long long i=5; n/i>0; i*=5) ans+=n/i;
+    	cout<<ans;
+    return 0;
+}

cses_twosets.cpp

@@ -0,0 +1,30 @@
+#include <bits/stdc++.h>
+using namespace std;
+#define int long long
+signed main()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+ 	int n; cin>>n;
+ 	if(((n*(n+1))/2) &1)
+ 	{
+ 		cout<<"NO";
+ 		return 0;
+ 	}
+ 	cout<<"YES\n";
+ 	int ans=(n*(n+1))/4;
+ 	vector<int> s1, s2;
+ 	for(int i=n; i>0; i--){
+ 		if(i<=ans){
+ 			s1.push_back(i);
+ 			ans-=i;
+ 		}
+ 		else s2.push_back(i);
+ 	}
+ 	cout<<s1.size()<<"\n";
+ 	for(auto it : s1) cout<<it<<" ";
+
+ 	cout<<"\n"<<s2.size()<<"\n";
+ 	for(auto it : s2) cout<<it<<" ";
+    return 0;
+}

leetcode_greycode.cpp

@@ -0,0 +1,11 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+int main()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+    int n; cin>>n;
+ 	for(int i=0; i<(1<<n); i++) cout<< (i^(i>>1)) <<" ";
+	return 0;
+}