减法算式20以内
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DEC_X_RANGE = (10..20) #第一个减数的范围
DEC_Y_RANGE = (1..20) #第二个减数的范围
LINE_CNTS = 5 #每行算式个数
DEC_FORMULA_CNTS = 100 #算式总的个数
res = {}
while res.size < DEC_FORMULA_CNTS do
x = rand(DEC_X_RANGE)
y = rand(DEC_Y_RANGE)
if (x-y) > 0
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
}
Ruby
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