20240429 Finished

src/problem/mod.rs

@@ -116,3 +116,4 @@ mod p392_is_subsequence;
 mod p167_two_sum_ii_input_array_is_sorted;
 mod p209_minimum_size_subarray_sum;
 mod p30_substring_with_concatenation_of_all_words;
+mod p76_minimum_window_substring;

src/problem/p76_minimum_window_substring.rs

@@ -0,0 +1,82 @@
+/**
+ * [76] Minimum Window Substring
+ */
+pub struct Solution {}
+
+
+// submission codes start here
+use std::collections::HashMap;
+
+impl Solution {
+    pub fn min_window(s: String, t: String) -> String {
+        let mut t_map = HashMap::new();
+
+        for c in t.chars() {
+            let entry = t_map.entry(c).or_insert(0);
+            *entry += 1;
+        }
+
+        let s : Vec<char> = s.chars().collect();
+        let mut s_map = HashMap::new();
+
+        let (mut i , mut j) = (0, 0);
+        let mut result_left = 0;
+        let mut result_length = usize::MAX;
+
+        while j < s.len() {
+            if t_map.contains_key(&s[j]) {
+                let entry = s_map.entry(s[j]).or_insert(0);
+                *entry += 1;
+            }
+
+            while Solution::check_map(&s_map, &t_map) && i <= j {
+                if j - i + 1 < result_length {
+                    result_length = j - i + 1;
+                    result_left = i;
+                }
+
+                if let Some(entry) = s_map.get_mut(&s[i]) {
+                    *entry -= 1;
+                }
+                i += 1;
+            }
+
+            j += 1;
+        }
+
+        if result_length == usize::MAX {
+            String::new()
+        } else {
+            s[result_left..result_left + result_length].iter().collect()
+        }
+    }
+
+    fn check_map(s : &HashMap<char, i32>, t : &HashMap<char, i32>) -> bool {
+        for (key, value) in t {
+            match s.get(key) {
+                Some(real_value) => {
+                    if *value > *real_value {
+                        return false;
+                    }
+                }
+                None => {
+                    return false;
+                }
+            }
+        }
+
+        true
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_76() {
+        assert_eq!("BANC".to_owned(), Solution::min_window("ADOBECODEBANC".to_owned(), "ABC".to_owned()));
+    }
+}