突击刷题： sqrt and power

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class Solution { public: /** * @param x: An integer * @return: The sqrt of x */ int sqrt(int x) { // write your code here if (x==0 || x==1) return x; int beg= 0; int end= x; while(beg<=end){ long mid=beg+(end-beg)/2; if (mid*mid>x) end=mid-1; else beg=mid+1; } return end; } };