1. An information processing apparatus for generating a similarity determination algorithm determining a similarity between a pair of data, the information processing apparatus comprising: a generating component configured to generate a feature-quantity-extraction expression list including a plurality of feature-quantity-extraction expressions, by updating the feature-quantity-extraction expression list of a preceding generation on the basis of an evaluation value of each of the feature-quantity-extraction expressions of a preceding generation, each of the feature-quantity-extraction expressions including an operator; a feature-quantity calculating component configured to input first teacher data and second teacher data into the feature-quantity-extraction expressions included in the feature-quantity-extraction expression list to calculate, for each of the feature-quantity-extraction expressions, a feature quantity corresponding to the first teacher data and a feature quantity corresponding to the second teacher data; an evaluation-value calculating component configured to calculate the evaluation value of each of the feature-quantity-extraction expressions included in the feature-quantity-extraction expression list using the calculated feature quantities and a known similarity between the first teacher data and the second teacher data; and an estimating component configured to estimate, by regression or by determination, a similarity calculation expression using: a distance between feature quantities calculated by inputting the first teacher data and the second teacher data into one of the feature-quantity-extraction expressions, and the known similarity between the first teacher data and the second teacher data.