diff --git a/src/problem/mod.rs b/src/problem/mod.rs
index 359b4e1..7b1d284 100644
--- a/src/problem/mod.rs
+++ b/src/problem/mod.rs
@@ -98,4 +98,7 @@ mod p80_remove_duplicates_from_sorted_array_ii;
 mod p169_majority_element;
 mod p189_rotate_array;
 mod p121_best_time_to_buy_and_sell_stock;
+mod p122_best_time_to_buy_and_sell_stock_ii;
+mod p55_jump_game;
+mod p45_jump_game_ii;
 mod p274_h_index;
\ No newline at end of file
diff --git a/src/problem/p122_best_time_to_buy_and_sell_stock_ii.rs b/src/problem/p122_best_time_to_buy_and_sell_stock_ii.rs
new file mode 100644
index 0000000..264c983
--- /dev/null
+++ b/src/problem/p122_best_time_to_buy_and_sell_stock_ii.rs
@@ -0,0 +1,44 @@
+/**
+ * [122] Best Time to Buy and Sell Stock II
+ */
+pub struct Solution {}
+
+// submission codes start here
+
+impl Solution {
+    pub fn max_profit(prices: Vec<i32>) -> i32 {
+        let mut result = 0;
+        let mut once_buy = 0;
+        let mut min_buy = prices[0];
+
+        for i in 1..prices.len() {
+            if prices[i] > prices[i - 1] {
+                once_buy = once_buy.max(prices[i] - min_buy);
+            } else if prices[i] < prices[i - 1] {
+                result += once_buy;
+                once_buy = 0;
+                min_buy = prices[i];
+            }
+        }
+
+        if once_buy != 0 {
+            result += once_buy;
+        }
+
+        result
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_122() {
+        assert_eq!(7, Solution::max_profit(vec![7, 1, 5, 3, 6, 4]));
+        assert_eq!(4, Solution::max_profit(vec![1, 2, 3, 4, 5]));
+        assert_eq!(0, Solution::max_profit(vec![7, 6, 4, 3, 2, 1]));
+    }
+}
diff --git a/src/problem/p45_jump_game_ii.rs b/src/problem/p45_jump_game_ii.rs
new file mode 100644
index 0000000..e38ec56
--- /dev/null
+++ b/src/problem/p45_jump_game_ii.rs
@@ -0,0 +1,41 @@
+/**
+ * [45] Jump Game II
+ */
+pub struct Solution {}
+
+// submission codes start here
+
+impl Solution {
+    pub fn jump(nums: Vec<i32>) -> i32 {
+        let mut dp = vec![i32::MAX; nums.len()];
+        dp[0] = 0;
+
+        for i in 0..nums.len() {
+            if dp[i] == i32::MAX {
+                continue;
+            }
+
+            for j in 1..=nums[i] as usize {
+                if i + j >= nums.len() {
+                    break;
+                }
+
+                dp[i + j] = dp[i + j].min(dp[i] + 1);
+            }
+        }
+
+        dp[nums.len() - 1]
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_45() {
+        assert_eq!(2, Solution::jump(vec![2, 3, 1, 1, 4]));
+    }
+}
diff --git a/src/problem/p55_jump_game.rs b/src/problem/p55_jump_game.rs
new file mode 100644
index 0000000..e4f2f0e
--- /dev/null
+++ b/src/problem/p55_jump_game.rs
@@ -0,0 +1,39 @@
+/**
+ * [55] Jump Game
+ */
+pub struct Solution {}
+
+// submission codes start here
+
+impl Solution {
+    pub fn can_jump(nums: Vec<i32>) -> bool {
+        let mut max_reach = 0;
+
+        for i in 0..nums.len() {
+            if i > max_reach {
+                return false;
+            }
+
+            max_reach = max_reach.max(i + nums[i] as usize);
+
+            if max_reach >= nums.len() - 1 {
+                return true;
+            }
+        } 
+
+        false
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_55() {
+        assert!(Solution::can_jump(vec![2, 3, 1, 1, 4]));
+        assert!(!Solution::can_jump(vec![3, 2, 1, 0, 4]));
+    }
+}