1 files changed, 15 insertions, 6 deletions

diff --git a/src/game.rs b/src/game.rs
index 2922121..4cb6fdd 100644
--- a/src/game.rs
+++ b/src/game.rs
@@ -317,16 +317,16 @@ impl GameState {
                     }
                 }
 
-                let num_dropped = drops.iter().map(|&d| d as usize).sum::<usize>();
+                let sum_dropped = drops.iter().map(|&d| d as usize).sum::<usize>();
                 let carry_capacity = self.size as usize;
-                if num_dropped > carry_capacity {
+                if sum_dropped > carry_capacity {
                     return Err(format!(
                         "A move may not exceed the carry capacity of {} stones.",
                         self.size
                     ));
                 }
 
-                if num_dropped != std::cmp::max(carry_capacity, stack_len) {
+                if sum_dropped != std::cmp::min(carry_capacity, stack_len) {
                     return Err(String::from(
                         "A move must effect the whole stack, up to the carry limit.",
                     ));
@@ -356,7 +356,7 @@ impl GameState {
                         }
                         if let Some(stack) = &self.board.get(self.pos_to_idx(&pos_new)) {
                             if stack.len() > 0 {
-                                match stack[0].stone {
+                                match stack[stack.len() - 1].stone {
                                     Stone::Capstone => {
                                         return Err(String::from(
                                             "A move may not cover a capstone.",
@@ -409,10 +409,19 @@ impl GameState {
         let idx = copy.pos_to_idx(&pos);
         let stack: &Stack = &self.board[self.pos_to_idx(pos)];
 
-        copy.board[idx].clear();
+        let len = copy.board[idx].len();
 
-        let num_drops = drops.len();
         let mut offset = 0;
+        if len > self.size as usize {
+            for _i in 0..self.size {
+                copy.board[idx].pop();
+            }
+            offset = self.size - 1;
+        } else {
+            copy.board[idx].clear();
+        }
+
+        let num_drops = drops.len();
         for drop_idx in 0..num_drops {
             let pos = pos_vec[pos_vec.len() - 1];
             let idx = copy.pos_to_idx(&pos);