diff --git a/CF1861D.cpp b/CF1861D.cpp
new file mode 100644
index 0000000..33296fb
--- /dev/null
+++ b/CF1861D.cpp
@@ -0,0 +1,50 @@
+#include<bits/stdc++.h>
+using namespace std;
+typedef long long LL ;
+typedef pair<int,int> pii;
+const int N = 2e5+100 , mod = 1e9+7;
+LL n ,a[N] , k ,T , dp[N][3] ;
+
+
+void AC() {
+    cin >> n ;
+    for (int i = 1; i <= n ; i++ ) cin >> a[i] ;
+    dp[1][0] = 0 ;dp[1][1] = 1;dp[1][2] = 1;
+    for (int i = 2 ; i <= n ; i++ ) {
+        LL mnn = (dp[i-1][0] < dp[i-1][1]) ? ( (dp[i-1][0] < dp[i-1][2]) ? dp[i-1][0] : dp[i-1][2] ) : ( (dp[i-1][1] < dp[i-1][2]) ? dp[i-1][1] : dp[i-1][2] );
+        if (a[i] == a[i-1]) {
+            dp[i][0] = dp[i-1][2] ;
+            dp[i][1] = 1LL + mnn;
+            dp[i][2] = dp[i-1][2] + 1;
+        } else if (a[i] > a[i-1]) {
+            dp[i][0] = mnn ;
+            dp[i][1] = min(dp[i-1][0] + 1 , dp[i-1][1] ) ;
+            dp[i][2] = dp[i-1][2] + 1;
+        } else {
+            dp[i][0] = dp[i-1][2] ;
+            dp[i][1] = 1LL + mnn ;
+            dp[i][2] = dp[i-1][2] ;
+        }
+    }
+    cout << min({dp[n][0] , dp[n][1] , dp[n][2]} ) << '\n';
+}
+
+int main() {
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);cout.tie(nullptr);
+    T = 1 ;
+    cin >> T ;
+    while (T--) {
+        AC();
+    }
+    return 0;
+}
+
+/*
+5
+00100
+01110
+11111
+11111
+11111
+ */
\ No newline at end of file
diff --git a/CF1864D.cpp b/CF1864D.cpp
new file mode 100644
index 0000000..382defa
--- /dev/null
+++ b/CF1864D.cpp
@@ -0,0 +1,61 @@
+#include<bits/stdc++.h>
+using namespace std;
+typedef long long LL ;
+typedef pair<int,int> pii;
+const int N = 3e3+10 , mod = 1e9+7;
+LL n , a[N][N] , s[N][N];
+
+
+void AC() {
+    cin >> n ;
+    for (int i = 1; i <= n ; i++ ) {
+        for (int j =1 ; j <= n ; j++ ) {
+            char c ; cin >> c ;
+            if (c == '0') a[i][j] = 0 ;
+            else a[i][j] = 1 ;
+            s[i][j] = 0 ;
+        }
+    }
+    LL ans = 0 ;
+    for (int i = 1; i <= n ; i++ ) {
+
+        for (int j =1 ; j <= n ; j++ ) {
+
+            if (s[i][j] & 1) { a[i][j] = 1 - a[i][j] ; }
+
+            if (a[i][j] & 1) {
+                a[i][j] = 1 - a[i][j] ;
+                ans+= 1;
+                s[i][j] += 1 ;
+            }
+            if (s[i][j] & 1) {
+                a[i+1][j] = 1 - a[i+1][j] ;
+                s[i+1][j-1]++ ; s[i+1][j+1] ++ ;
+                if (j != 1 && j != n) s[i+2][j] += s[i][j] ;
+            }
+
+        }
+
+    }
+    cout << ans << '\n';
+}
+
+int main() {
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);cout.tie(nullptr);
+    int T = 1 ;
+    cin >> T ;
+    while (T--) {
+        AC();
+    }
+    return 0;
+}
+
+/*
+5
+00100
+01110
+11111
+11111
+11111
+ */
\ No newline at end of file
diff --git a/CF1870D.cpp b/CF1870D.cpp
new file mode 100644
index 0000000..569ffb5
--- /dev/null
+++ b/CF1870D.cpp
@@ -0,0 +1,43 @@
+#include<bits/stdc++.h>
+using namespace std;
+typedef long long LL ;
+typedef pair<int,int> pii;
+const int N = 2e5+100 , mod = 1e9+7;
+LL n ,ans[N],a[N] , k , mn ,T ;
+
+
+void AC() {
+    cin >> n ;
+    for( int i =0 ;  i <= n+5 ; i++ ) ans[i] = 0 ;
+    ans[0] = INT_MAX , mn = INT_MAX;
+    for (int i =1 ; i <= n ; i++ ) { cin >> a[i] ; }
+    cin >> k ;
+    for (int i = n ; i >= 1 ; i-- ) mn = min( mn , a[i]) , a[i] = mn ;
+    for (int i = 1 ; i <= n ; i++ ) {
+        if (a[i] == a[i-1]) ans[i] = ans[i-1] ;
+        else ans[i] = min(ans[i-1] , k/(a[i]-a[i-1])) ;
+        k = k - (a[i] - a[i-1]) * ans[i];
+        cout << ans[i] <<  " " ;
+    }
+    cout << '\n';
+}
+
+int main() {
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);cout.tie(nullptr);
+    T = 1 ;
+    cin >> T ;
+    while (T--) {
+        AC();
+    }
+    return 0;
+}
+
+/*
+5
+00100
+01110
+11111
+11111
+11111
+ */