diff options
| -rw-r--r-- | src/stack.zig | 51 |
1 files changed, 49 insertions, 2 deletions
diff --git a/src/stack.zig b/src/stack.zig index ce70df0..1a70be1 100644 --- a/src/stack.zig +++ b/src/stack.zig @@ -74,8 +74,55 @@ pub const Stack = struct { try s.swap(); try std.testing.expectEqual(s.popVector(), @as(vector, [2]i64{ 2, 0 })); } - //pub fn transfert(toss: *Stack, soss: *Stack, n: u64) !void { - //} + pub fn transfert(toss: *Stack, soss: *Stack, n: u64) !void { + // Implements a value transfert between two stacks, intended for use with the '{' + // (aka begin) and '}' (aka end) stackstack commands + try toss.data.ensureUnusedCapacity(n); + var i: usize = n; + while (i >= std.math.min(soss.data.items.len, n) + 1) : (i -= 1) { + toss.data.appendAssumeCapacity(0); + } + while (i >= 1) : (i -= 1) { + toss.data.appendAssumeCapacity(soss.data.items[soss.data.items.len - i]); + } + if (soss.data.items.len >= n) { + soss.data.items.len -= n; + } else { + soss.data.items.len = 0; + } + } + test "transfert" { + var empty = try Stack.init(std.testing.allocator); + defer empty.deinit(); + var empty2 = try Stack.init(std.testing.allocator); + defer empty2.deinit(); + try empty.transfert(empty2, 4); + const emptyResult = [_]i64{ 0, 0, 0, 0 }; + try std.testing.expectEqualSlices(i64, empty.data.items, emptyResult[0..]); + const empty2Result = [_]i64{}; + try std.testing.expectEqualSlices(i64, empty2.data.items, empty2Result[0..]); + try empty.transfert(empty2, 32); + try std.testing.expectEqual(empty.data.items.len, 36); + empty.clear(); + var some = try Stack.init(std.testing.allocator); + defer some.deinit(); + try some.push(2); + try empty.transfert(some, 3); + const emptyResult2 = [_]i64{ 0, 0, 2 }; + try std.testing.expectEqualSlices(i64, empty.data.items, emptyResult2[0..]); + try std.testing.expectEqualSlices(i64, some.data.items, empty2Result[0..]); + empty.clear(); + var full = try Stack.init(std.testing.allocator); + defer full.deinit(); + try full.push(1); + try full.push(2); + try full.push(3); + try empty.transfert(full, 2); + const emptyResult3 = [_]i64{ 2, 3 }; + try std.testing.expectEqualSlices(i64, empty.data.items, emptyResult3[0..]); + const fullResult = [_]i64{1}; + try std.testing.expectEqualSlices(i64, full.data.items, fullResult[0..]); + } }; test "all" { |