在电子表格中查找循环引用的算法

I have a spreadsheet application with formulas. I am looking for the best algorithm for detecting circular references among the formulas. The current approach I have is slow and uses too much memory when long chains of calculations are in place with the formulas. It involves keeping sets of all dependents for each formula. So if the first column of cells each had a formula with a reference to the cell before it, the first cell's set would be empty. The 2nd cell's set would only contain the first cell, the 3rd cell's set would contain cells 1 and 2, ..., the 1000th cell's set would contain the 999 cells before it. When a new formula was introduced, its dependents set is built and if the set contains the new formula, there is a circular reference. But obviously, for this scenario, the time and memory required grows exponentially.I have a spreadsheet application with formulas.