Leah Brumgard majors in studio art at Swarthmore College, Jeff Novak in math, and William Colgan in biology.

But all three have a second major: Computer science.

The trio is far from unusual. More than 70 students are dual majoring in computer science and another subject this year at the prestigious liberal arts college in Delaware County, and more than 50 have selected computer science as their sole major.

Computer science has become the second most popular major on the 1,620-student campus, behind economics. It's a far shift from as recently as 2010, when there were fewer than a dozen computer-science graduates.

Across the country, the number of computer science majors at doctoral institutions has more than tripled in the last decade. It's much hotter than it was during the dot-com blitz in the late 1990s, according to the national Computing Research Association.

The group refers to the current surge as "Generation CS," fueled by the pervasiveness of computing across society and the plethora of jobs, some with six-figure salaries and eye-popping signing bonuses.

Computation has become important to literally every field, whether it's digital humanities or software-writing skills needed for economics.

"Math used to be the language of science, and now computer science is becoming another language of science, and not just science, but social science and humanities as well," said Lisa Meeden, a computer science professor at Swarthmore. "Everybody feels that they need some computer science knowledge."

The spurt also is occurring at big universities, including Temple, Rutgers, Villanova, Penn State, La Salle, Lehigh, and Drexel, where the number of computer science majors has in some cases more than doubled in the last five years and where the influx might be expected. Temple, for instance, had 294 students majoring solely in computer science in fall 2012, compared with 675 now, and many more dual majoring. Rutgers-New Brunswick has grown from 207 in 2011-12 to 937 last year.

But it's also happening at other small, elite liberal arts colleges, where the increase may seem counterintuitive, including Haverford and Bryn Mawr.

"They still at the end of the day want to get jobs when they graduate, and these are hot fields for jobs," said Stuart Zweben, of the Computing Research Association and professor emeritus of computer science and engineering at Ohio State University. "Whether they go to a big school or small school, that's something that's on their minds."

Nearly half of all students at Swarthmore take intro to computer science. Many hadn't been exposed to it in high school or if they were, only in a limited way, professors say. So when they take that course, their interest is sparked.

"I realized it was changing the way that I thought," said Sarah Depew, 21, a Bryn Mawr student. "I was approaching problems in a different way. And I thought, 'You know what? This is really interesting. I want to keep doing this.'"

The junior from Monument, Colo., is majoring in math and computer science.

Computer science majors start out learning how to program and construct algorithms and by the time they graduate, they will understand theory, applications, and systems.

Novak, 22, of West Chester, said he had so much fun in the intro class that he decided to major in it.

"You kind of explore this creativity and small problem solving," he said.

But it's not just fun that is attracting students.

The plentiful — and in many cases lucrative — job prospects also are a lure.

"There's going to be so many options after you graduate," said Brumgard, 20, a junior from Hanover in York County. "It's not like you're destined to just sit at a computer every day in an office and write code. There are a lot of different paths that you can take with it."

Students are being recruited by Google, Apple, Microsoft, and other high-tech companies, as well as financial firms.

Dianna Xu, computer science department chair at Bryn Mawr, recalled a conversation she overheard among seniors last year.

"One student said, 'Oh, Facebook is offering me $120 or $130K a year, and they're giving me $100,000 start-up cash. Should I take it?'" Xu said. "The rest of the students go, 'No, no, wait for a better offer.'"

Colgan, 21, a junior from Montvale, N.J., hopes to become a research biologist and use his computing knowledge in his research. Other Swarthmore graduates have gone on to such jobs as clinical research associate for a Seattle hospital, project manager for Facebook, and software development engineer for Amazon.

The burst in interest among majors — and non-majors who want to take courses — has left computer science departments scrambling to find enough qualified professors to staff classes and students jockeying to get classes they want and need to graduate.

Students at Haverford, Bryn Mawr, and Swarthmore sometimes take classes at one of the other campuses, or at the University of Pennsylvania.

"I've been lotteried out of things, but if you go and just sit in the back of the class and keep talking to the professor, you'll eventually get in," Colgan advises.

Meeden said students typically get at least one class per semester and make progress toward their degree. Novak finished classes for his major during junior year, but would have liked to take more.

"I wasn't able to go into whatever class I wanted after that," he said.

Swarthmore's department has gone from four to nine computer science professors in seven years but, as at Bryn Mawr, professors say it's not enough.

"We think we probably need at least 12," Meeden said.

"And we'll still have average class sizes of 40," noted Richard Wicentowski, Swarthmore's computer science department chair.

The growing department has converted a lab and hallway space into offices and took over room in the chemistry department. Construction on campus is expected to alleviate that crunch in the next few years.

Hiring professors has posed a challenge, too, Wicentowski said.

"Almost every school now is trying to hire new faculty," he said. "And the number of people getting Ph.D.s hasn't dramatically increased."

Xu said Bryn Mawr has not been able to fill an adjunct position since 2014. Non-majors who want to take classes sometimes can't get in.

"They're not happy about this and they are complaining a lot," she said.

Bryn Mawr President Kim Cassidy said the college is evaluating the department's expanding needs and is preparing to open a computer science teaching laboratory as part of a $40 million science center renovation.

The college also is emphasizing digital skills across subjects, she said. The school spent a year interviewing faculty, students, employers, alumni, and parents about digital skills students will need in their personal lives and for work, and then "mapped" those skills across the curriculum.

"No matter what a student's interest is," Cassidy said, "they are realizing they need to have digital skills and digital fluency."