In mathematics, the Robinson–Schensted–Knuth correspondence, also referred to as the RSK correspondence or RSK algorithm, is a combinatorial bijection between matrices with non-negative integer entries and pairs of semistandard Young tableaux of equal shape, whose size equals the sum of the entries of . More precisely the weight of is given by the column sums of , and the weight of by its row sums. It is a generalization of the Robinson–Schensted correspondence, in the sense that taking to be a permutation matrix, the pair will be the pair of standard tableaux associated to the permutation under the Robinson–Schensted correspondence.