diff --git a/ArrayDescription.cpp b/ArrayDescription.cpp
new file mode 100644
index 0000000..cdca738
--- /dev/null
+++ b/ArrayDescription.cpp
@@ -0,0 +1,72 @@
+#include <iostream>
+#include <vector>
+#include <string>
+#include <climits>
+#include <set>
+#include <algorithm>
+using namespace std;
+
+#define ll long long int
+
+#define OJ                            \
+    freopen("input.txt", "r", stdin); \
+    freopen("output.txt", "w", stdout);
+#define FIO                           \
+    ios_base::sync_with_stdio(false); \
+    cin.tie(NULL);                    \
+    cout.tie(NULL);
+
+int main()
+{
+    //OJ;
+    int mod = 1e9 + 7;
+    int n, m;
+    cin >> n >> m;
+    vector<vector<int>> dp(n, vector<int>(m + 1, 0));
+    int x0;
+    cin >> x0;
+    if (x0 == 0)
+    {
+        fill(dp[0].begin(), dp[0].end(), 1);
+    }
+    else
+    {
+        dp[0][x0] = 1;
+    }
+    for (int i = 1; i < n; i++)
+    {
+        int x;
+        cin >> x;
+        if (x == 0)
+        {
+            for (int j = 1; j <= m; j++)
+            {
+                for (int k : {j - 1, j, j + 1})
+                {
+                    if (k >= 1 && k <= m)
+                    {
+                        (dp[i][j] += dp[i - 1][k]) %= mod;
+                    }
+                }
+            }
+        }
+        else
+        {
+            for (int k : {x - 1, x, x + 1})
+            {
+                if (k >= 1 && k <= m)
+                {
+                    (dp[i][x] += dp[i - 1][k]) %= mod;
+                }
+            }
+        }
+    }
+    
+
+    int ans = 0;
+    for(int i=1; i<=m; i++){
+        (ans+= dp[n-1][i])%=mod;
+    }
+
+    cout << ans << endl;
+}
\ No newline at end of file
diff --git a/BookShop.cpp b/BookShop.cpp
new file mode 100644
index 0000000..2d659ec
--- /dev/null
+++ b/BookShop.cpp
@@ -0,0 +1,54 @@
+#include <iostream>
+#include <vector>
+#include <string>
+#include <climits>
+#include <set>
+#include <algorithm>
+using namespace std;
+
+#define ll long long int
+
+#define OJ                            \
+    freopen("input.txt", "r", stdin); \
+    freopen("output.txt", "w", stdout);
+#define FIO                           \
+    ios_base::sync_with_stdio(false); \
+    cin.tie(NULL);                    \
+    cout.tie(NULL);
+
+int main()
+{
+    OJ;
+    int n, maxBooks;
+    cin >> n >> maxBooks;
+    int* prices = new int[n];
+    int* pages = new int[n];
+
+    for(int i=0; i<n; i++){
+        cin >> prices[i];
+    }
+
+    for(int i=0; i<n; i++){
+        cin >> pages[i];
+    }
+    
+    vector<vector<int>> dp(n+1, vector<int>(maxBooks+1, 0));
+    for(int i=1; i<=n; i++){
+        for(int j= 0; j <=maxBooks; j++){
+            dp[i][j] = dp[i-1][j];
+            int left = j-prices[i-1];
+            if(left>=0){
+                dp[i][j] = max(dp[i][j], dp[i-1][left]+pages[i-1]);
+            }
+
+        }
+    }
+
+    for(int i=0; i<=n; i++){
+        for(int j=0; j<=maxBooks; j++){
+            cout << dp[i][j] << " ";
+        }
+        cout << endl;
+    }
+
+}
\ No newline at end of file
diff --git a/CoinCombination1.cpp b/CoinCombination1.cpp
new file mode 100644
index 0000000..7204a86
--- /dev/null
+++ b/CoinCombination1.cpp
@@ -0,0 +1,49 @@
+#include <iostream>
+#include <vector>
+#include <climits>
+#include <algorithm>
+using namespace std;
+
+#define ll long long int
+
+#define OJ                            \
+    freopen("input.txt", "r", stdin); \
+    freopen("output.txt", "w", stdout);
+#define FIO                           \
+    ios_base::sync_with_stdio(false); \
+    cin.tie(NULL);                    \
+    cout.tie(NULL);
+
+void BottomUp(int target, vector<int> c, int n)
+{
+    int mod = 1e9 + 7;
+    vector<int> dp(target + 1, 0);
+    dp[0] = 1;
+    for (int i = 1; i <= target; i++)
+    {
+        for (int j = 0; j < n; j++)
+        {
+            if (i - c[j] >= 0)
+            {
+                (dp[i] += dp[i - c[j]]) %= mod;
+            }
+        }
+    }
+    cout << dp[target] << endl;
+}
+
+int main()
+{
+    //OJ;
+    int n, target;
+    cin >> n >> target;
+    vector<int> c(n);
+    for (int &v : c)
+    {
+        cin >> v;
+    }
+
+    BottomUp(target, c, n);
+
+    return 0;
+}
\ No newline at end of file
diff --git a/CoinCombination2.cpp b/CoinCombination2.cpp
new file mode 100644
index 0000000..d986446
--- /dev/null
+++ b/CoinCombination2.cpp
@@ -0,0 +1,40 @@
+#include <iostream>
+#include <vector>
+#include <climits>
+#include <algorithm>
+using namespace std;
+
+#define ll long long int
+
+#define OJ                            \
+    freopen("input.txt", "r", stdin); \
+    freopen("output.txt", "w", stdout);
+#define FIO                           \
+    ios_base::sync_with_stdio(false); \
+    cin.tie(NULL);                    \
+    cout.tie(NULL);
+
+int main()
+{
+    //OJ;
+    int n, target;
+    cin >> n >> target;
+    vector<int> c(n);
+    for (int &v : c)
+        cin >> v;
+    
+    int mod = 1e9+7;
+    vector<vector<int>> dp(n+1, vector<int>(target+1, 0));
+    dp[0][0] = 1;
+    for(int i=1; i<=n; i++){
+        for(int j=0; j<=target; j++){
+            dp[i][j] = dp[i-1][j];
+            if(j-c[i-1]>=0){
+                (dp[i][j]+=dp[i][j-c[i-1]])%=mod;
+            }
+        }
+    }
+
+    cout << dp[n][target] << endl;
+    return 0;
+}
\ No newline at end of file