diff --git a/src/double_week_125/mod.rs b/src/double_week_125/mod.rs
new file mode 100644
index 0000000..17371d2
--- /dev/null
+++ b/src/double_week_125/mod.rs
@@ -0,0 +1,3 @@
+mod problem1;
+mod problem2;
+mod problem3;
\ No newline at end of file
diff --git a/src/double_week_125/problem1.rs b/src/double_week_125/problem1.rs
new file mode 100644
index 0000000..a861d38
--- /dev/null
+++ b/src/double_week_125/problem1.rs
@@ -0,0 +1,15 @@
+pub struct Solution;
+
+impl Solution {
+    pub fn min_operations(nums: Vec<i32>, k: i32) -> i32 {
+        let mut result = 0;
+
+        for i in nums {
+            if i < k {
+                result += 1;
+            }
+        }
+
+        result
+    }
+}
\ No newline at end of file
diff --git a/src/double_week_125/problem2.rs b/src/double_week_125/problem2.rs
new file mode 100644
index 0000000..7f9c60c
--- /dev/null
+++ b/src/double_week_125/problem2.rs
@@ -0,0 +1,29 @@
+pub struct Solution;
+
+use std::collections::BinaryHeap;
+use std::cmp::Reverse;
+
+impl Solution {
+    pub fn min_operations(nums: Vec<i32>, k: i32) -> i32 {
+        let mut heap = BinaryHeap::new();
+        let k = k as i64;
+        
+        for i in nums {
+            let i = i as i64;
+            heap.push(Reverse(i));
+        }
+
+        let mut result = 0;
+
+        while heap.peek().unwrap().0 < k {
+            let x = heap.pop().unwrap().0;
+            let y = heap.pop().unwrap().0;
+
+            heap.push(Reverse(x + y + x.min(y)));
+            result += 1;
+        }
+
+
+        result
+    }
+}
\ No newline at end of file
diff --git a/src/double_week_125/problem3.rs b/src/double_week_125/problem3.rs
new file mode 100644
index 0000000..8c469e1
--- /dev/null
+++ b/src/double_week_125/problem3.rs
@@ -0,0 +1,71 @@
+pub struct Solution;
+
+use std::collections::HashMap;
+
+impl Solution {
+    pub fn count_pairs_of_connectable_servers(edges: Vec<Vec<i32>>, signal_speed: i32) -> Vec<i32> {
+        let n = edges.len();
+        let mut graph = vec![vec![];n];
+        let signal_speed = signal_speed as i64;
+
+        for edge in &edges {
+            let x = edge[0] as usize;
+            let y = edge[1] as usize;
+            let weight = edge[2] as i64;
+
+            graph[x].push((y, weight));
+            graph[y].push((x, weight));
+        }
+
+        let mut connection = vec![(0,0);n];
+        for next in &graph[0] {
+
+        }        
+
+        let mut result = Vec::with_capacity(n);
+
+        result
+    }
+
+    fn dfs(graph: &Vec<Vec<(usize, i64)>>, conection: &mut Vec<(i64, usize)>, now: usize, pre: usize, distance: i64, start: usize) {
+        for next in &graph[now] {
+            if next.0 == pre {
+                continue;
+            }
+
+            conection[next.0] = (distance + next.1, start);
+
+            Solution::dfs(graph, conection, next.0, now, distance + next.1, start);
+        }
+    }
+
+    fn tree_dp(graph: &Vec<Vec<(usize, i64)>>, conection: &mut Vec<(i64, usize)>, result: &mut Vec<i32>, 
+        now: usize, pre: usize, signal_speed: i64) {
+        let mut count = HashMap::new();
+
+        for node in conection {
+            if node.0 % signal_speed == 0 {
+                let entry = count.entry(node.1).or_insert(0);
+
+                *entry += 1;
+            }
+        }
+
+        let count: Vec<&i32> = count.values().collect();
+        let mut ans = 0;
+
+        for i in 0..(count.len() - 1) {
+            for j in (i + 1)..count.len() {
+                ans += count[i] * count[j];
+            }
+        }
+
+        result[now] = ans;
+
+        for next in &graph[now] {
+            if next.0 == pre {
+                continue;
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/lib.rs b/src/lib.rs
index 144c1b0..eb9b5e5 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2,3 +2,4 @@
 pub mod util;
 pub mod problem;
 pub mod week_385;
+pub mod double_week_125;