Number Placement Sandbox

Author and test graph-based number placement puzzles with sum constraints, adjacency rules, and target-answer variants.

Edit the JSON config directly, validate it with the solver, and preview the interactive using the same reusable component as problem pages.

{
  "layoutPreset": "star_9",
  "title": "Arrange 1 to 9 on the star",
  "prompt_md": "Place the digits **1** to **9** in the circles so that every straight line of three circles sums to **15**.",
  "tokens": [
    1,
    2,
    3,
    4,
    5,
    6,
    7,
    8,
    9
  ],
  "nodes": [
    {
      "id": "c",
      "prefilledValue": 5
    }
  ],
  "constraints": {
    "sumGroups": [
      {
        "id": "vertical",
        "nodeIds": [
          "n",
          "c",
          "s"
        ],
        "targetSum": 15,
        "label": "Vertical"
      },
      {
        "id": "horizontal",
        "nodeIds": [
          "w",
          "c",
          "e"
        ],
        "targetSum": 15,
        "label": "Horizontal"
      },
      {
        "id": "diag-rising",
        "nodeIds": [
          "sw",
          "c",
          "ne"
        ],
        "targetSum": 15,
        "label": "Diagonal"
      },
      {
        "id": "diag-falling",
        "nodeIds": [
          "nw",
          "c",
          "se"
        ],
        "targetSum": 15,
        "label": "Diagonal"
      }
    ]
  },
  "validation": {
    "requireAtLeastOneSolution": true,
    "requireUniqueSolution": false
  }
}

Validation

Has solution256 solutions

Solver reached the configured solution cap before exhausting the search tree.

Arrange 1 to 9 on the star

Place the digits 1 to 9 in the circles so that every straight line of three circles sums to 15 .

Solver reached the configured solution cap before exhausting the search tree.

Groups 0/4

Tokens

Selection

Node: none

Token: none

Live feedback

Current placement is still consistent.