20241001 finished.

src/problem/mod.rs

@@ -250,4 +250,5 @@ mod p2535_difference_between_element_sum_and_digit_sum_of_an_array;
 mod p2516_take_k_of_each_character_from_left_and_right;
 mod p2286_booking_concert_tickets_in_groups;
 mod p2073_time_needed_to_buy_tickets;
-mod p1845_seat_reservation_manager;
+mod p1845_seat_reservation_manager;
+mod p983_minimum_cost_for_tickets;

src/problem/p983_minimum_cost_for_tickets.rs

@@ -0,0 +1,51 @@
+/**
+ * [983] Minimum Cost For Tickets
+ */
+pub struct Solution {}
+
+
+// submission codes start here
+use std::collections::HashSet;
+
+impl Solution {
+    pub fn mincost_tickets(days: Vec<i32>, costs: Vec<i32>) -> i32 {
+        let mut memory = vec![None; 366];
+        let days: HashSet<usize> = days.iter().map(|x| *x as usize).collect();
+        
+        Self::dp(1, &mut memory, &days, &costs)
+    }
+    
+    fn dp(day: usize, memory: &mut Vec<Option<i32>>, days: &HashSet<usize>, costs: &Vec<i32>) -> i32 {
+        if day > 365 {
+            return 0;
+        }
+        
+        if let Some(result) = memory[day] {
+            return result;
+        }
+        
+        let result = if days.contains(&day) {
+            (Self::dp(day + 1, memory, days, costs) + costs[0])
+                .min(Self::dp(day + 7, memory, days, costs) + costs[1])
+                .min(Self::dp(day + 30, memory, days, costs) + costs[2])
+        } else { 
+            Self::dp(day + 1, memory, days, costs)
+        };
+        
+        memory[day] = Some(result);
+        result
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_983() {
+        assert_eq!(11, Solution::mincost_tickets(vec![1, 4, 6, 7, 8, 20], vec![2, 7, 15]));
+        assert_eq!(17, Solution::mincost_tickets(vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 30, 31], vec![2, 7, 15]));
+    }
+}