ADD_X_RANGE = (1..20) #第一个加数的范围 ADD_Y_RANGE = (1..20) #第二个加数的范围 ADD_RES_MAX = 20 #加法和最大值 ADD_RES_MIN = 10 #加法和最小值 ADD_FORMULA_CNTS = 100 #算式总的个数 LINE_CNTS = 5 #每行算式个数 res = {} while res.size < ADD_FORMULA_CNTS do x = rand(ADD_X_RANGE) y = rand(ADD_Y_RANGE) if (x+y) <= ADD_RES_MAX && (x+y) > ADD_RES_MIN key = sprintf("%d+%d", x, y) str = sprintf("%-2d + %-2d = ", x, y) res[key] = str end end line = 0 res.each{|x,y| printf(y) line = line + 1 if line == LINE_CNTS puts "" puts "" line = 0 end }