查找字符串中数字序列的最小数量

I am confused as how to separate a sequence of numbers in a string, which are separated by spaces and finding the minimum among them (e.g. "4 3 2 1".)I have an idea of separating the values using a scanner and parsing them, but I don't know how to use them when it's a string. Please help! Thanks!I am confused as how to separate a sequence of