[Lintcode]sqrt (x)

Method 1: Two points

1 classSolution {2  Public:3     /**4 * @param x:an integer5 * @return: The sqrt of x6      */7     intsqrtintx) {8         //Write your code here9         Long LongL =1, r =x;Ten          while(l<R) One         { A             Long Longm = (l+r)/2; -             if(m*m>x) r = m1; -             Else the             { -                 if((m+1) * (m+1) >x)returnm; -                 Else -                 { +L = m+1; -                 } +             } A         } at     } -};

Method 2: Newton's method

Ask for the square root of x, first any number y, if y is not the square root of x or the precision is not enough, then y = (y+x/y)/2, loop until the square root of x or achieve our satisfactory accuracy, each cycle will make y closer to the square root of x.

1#include <cmath>2 classSolution {3  Public:4     /**5 * @param x:an integer6 * @return: The sqrt of x7      */8     intsqrtintx) {9         //Write your code hereTen         Doubley =1.0; One          while(ABS (Y*Y-X) >1) Ay = (y+x/y)/2; -         return(int) y; -     } the};

[Lintcode]sqrt (x)