Ten years ago, girls were so scarce in high school computer science classes that the number of female students taking Advanced Placement tests in that subject could be counted on one hand in nine states. In five others, there were none. Latino and African American students were also in short supply, a problem that has bedeviled educators for years and hindered efforts to diversify the high-tech workforce. Now, an expansion of AP computer science classes is helping to draw more girls and underrepresented minorities into a field of growing importance for schools, universities and the economy. Testing totals for female, black and Latino students all doubled in 2017, following the national debut of an AP course in computer science principles. It joined a longer-established AP course focused on the programming language Java. Racial and gender imbalances persist. But education leaders said the data show a significant advance in a quest to banish the stereotype that computer science is mainly for coding geeks who tend to be white or Asian American boys.