She was brilliant but troubled.
Before she flung herself into the Hudson River over an allegation of cheating, Omotayo Adeoye had the world at her feet.
She was an honor student at one of the city’s most competitive high schools, took advanced classes at Mount Sinai School of Medicine, and was waiting to hear if she’d qualify for a National Achievement Scholarship for college.
“Mad colleges want me!” a neighbor recently overheard the proud Bronx teen boast.
But as divers continued searching for her body off Washington Heights on Saturday, a darker picture emerged of the sadness and struggle surrounding the junior at Harlem’s HS for Math, Science and Engineering.
Adeoye, a 17-year-old Nigerian immigrant of Muslim faith, drowned herself Thursday less than two hours after her German-language teacher, Eva Malikova, screamed at her for peeking at her cellphone during a test.
“I just want to go away forever on the bottom of the river,” the humiliated girl wrote on the test, turning it into a suicide note, sources said.
Her note also included a reference to “dignity,” a source added.
But for at least two years prior to her death plunge, the girl struggled with depression and had run away from home repeatedly in the past two years, friends, fellow students and others who knew her told The Post.
“Her family was very worried. They found her walking near the river in Manhattan [last year],” said Pedro Jimenez, the superintendent at Adeoye’s Mott Haven apartment building.
One neighbor, Manzel Jones, 44, said the girl never seemed to socialize.
“It’s either she was going to school, doing the laundry or playing basketball in the park by herself,” Jones recalled.
“She walked with her head down. She wouldn’t look at you, never made eye contact. She seemed stressed all the time.”
“When she ran away [earlier this year], she was gone for three days,” Jones added. “Her mother was lying on the floor in the hallway, crying and knocking on doors, asking, ‘Have you seen my daughter? She didn’t come home from school.’
“When she came back, she still looked depressed,” he said.
Adeoye could sometimes be heard arguing heatedly with her mother in their Mott Haven apartment. She would walk with downcast eyes through the building’s halls and lobby, said neighbors.
“You could see the negativity in her. She always looked sad and walked with her head down,” said neighbor Jelianys Perez, 16. “She didn’t speak to anyone.”
More than a year ago, Adeoye stopped wearing a traditional headscarf, or hijab, without explanation, recalled Comfort Olowo, who played basketball with her on the school team.
Olowo, of Canarsie, Brooklyn, said that as somber as Adeoye could be at home, she was a lighthearted and optimistic presence on the team.
“We’d be losing a game, but she’d be, ‘It’s OK. We can still get this,’ ” Olowo recalled.
Another teammate, Donna Fintzi, 18, of Riverdale in The Bronx, agreed.
“She’s a really bubbly girl. She’s always smiling,” Fintzi said.
Junior Sebastian Villada, 17, of Woodside, Queens, said that in ninth and 10th grades, Adeoye was in her class’ top 10 for grades. Those grades fell slightly this year, “but she still had a 90-plus average,” he said.
Junior Natalie Sharp, 17, of Chelsea, said: “She was really nice and really funny. That’s what everybody remembers about her.”
“She didn’t talk to many people, but if you talked to her, she’d talk to you.”
“We had gym class together last year, and she was really fast. I’d ask her how she was so fast, and she’d crack jokes and say, ‘I’m from Nigeria — it’s part of my culture,’ ” Sharp said.
After gym class, “to prove her speed, she’d run for the halal cart and get a doughnut and still beat me upstairs, and then she’d give me a smile and we’d laugh.”
In response to the apparent suicide — the 14th among students this school year — Chancellor Carmen Fariña announced Saturday that she has lifted the system-wide hiring freeze on guidance counselors.
Malikova, who law-enforcement sources say unwittingly spurred the girl’s apparent suicide, could not be reached for comment Saturday.
Additional reporting by Natasha Velez