Add a lot of cses dp problems

I had some free time to just do them, they were pretty easy though.

CSES Problem Set/Array Description.cpp

@@ -0,0 +1,119 @@
+/* Problem URL: https://cses.fi/problemset/task/1746 */
+
+#include <bits/stdc++.h>
+
+using namespace std;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (size_t i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (size_t i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const ll mod = 1e9 + 7;
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    int n, m;
+    cin >> n >> m;
+
+    vi nums(n);
+    cin >> nums;
+
+    vvl dp(n, vl(m + 1, 0));
+    if (nums[0] > 0) {
+        dp[0][nums[0]] = 1;
+    } else {
+        fill(dp[0].begin(), dp[0].end(), 1);
+        dp[0][0] = 0;
+    }
+
+    nrep(i, 1, n) {
+        if (nums[i] > 0) {
+            ll ans = dp[i - 1][nums[i]];
+            if (nums[i] < m) {
+                ans += dp[i - 1][nums[i] + 1];
+            }
+            if (nums[i] > 1) {
+                ans += dp[i - 1][nums[i] - 1];
+            }
+            dp[i][nums[i]] = ans % mod;
+            continue;
+        }
+
+        for (size_t j = 1; j <= m; j++) {
+            dp[i][j] += dp[i - 1][j];
+            if (j > 1) {
+                dp[i][j] += dp[i - 1][j - 1];
+            }
+            if (j < m) {
+                dp[i][j] += dp[i - 1][j + 1];
+            }
+            dp[i][j] %= mod;
+        }
+    }
+
+    cout << accumulate(dp[n - 1].begin(), dp[n - 1].end(), 0LL) % mod << '\n';
+}