<span style="font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);"><span style="font-size:14px;">题意：给出直线ax+by+c=0的参数a, b, c，求直线在 x ∈[x1, x2]，y ∈[y1, y2] 上有多少整点。</span></s