No, Albert Einstein did not come up with the idea of strings. The concept of strings emerged much later in the development of theoretical physics, specifically in the field of string theory.
String theory, also known as superstring theory, is a theoretical framework that attempts to unify the fundamental forces of nature, including gravity, with the other three fundamental forces (electromagnetic, strong nuclear, and weak nuclear forces). It suggests that the fundamental constituents of the universe are not point-like particles but rather tiny, one-dimensional entities called strings.
The development of string theory began in the late 1960s and early 1970s, primarily by theoretical physicists working independently of Einstein. The key figures in the early development of string theory were Gabriele Veneziano, who discovered the Veneziano amplitude in 1968, and Leonard Susskind, Holger Bech Nielsen, and Yoichiro Nambu, who independently proposed the idea of a string interpretation of Veneziano's work in 1970.
Einstein's work, on the other hand, was primarily focused on general relativity, which describes the force of gravity. While Einstein made significant contributions to theoretical physics, his work predates the development of string theory by several decades.