Is bringing breakfast to female students who achieved the highest grades in an exam—based on a prior agreement—considered among the forbidden acts?

The agreement among friends that the one who excels in exams provides food for them is permissible if it is an act of generosity and an expression of joy at the achievement. It is a promise of a gift, provided that it is done willingly and not out of shyness. It is forbidden to take money out of shyness. Betting with money is not permissible except in cases specifically exempted by Islamic law, such as races involving horses or camels, or archery. Anything other than these is considered consuming wealth unjustly and a form of gambling (maysir). As for a person saying: "If this matter is achieved for me, then you shall have such and such from me," this falls under the category of a promise, and fulfilling it is legislated if it is facilitated.