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开平方函数的C语言实现
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// Created by zscself on 2016/12/20. | |
#include <stdio.h> | |
double ssqrt(int v,double t){ | |
double double_v = (double) v; | |
double mid,midd,midSubT,midAddT,low = 0, high = double_v; | |
while(1){ | |
mid = (low + high)/2; | |
midd = mid * mid; | |
midSubT = mid - t; | |
midAddT = mid + t; | |
if( midd == v){ | |
double_v = mid; | |
}else if( midd > v ){ | |
if(midSubT * midSubT < v){ | |
double_v = mid; | |
break; | |
} | |
high = high-t; | |
}else{ | |
if(midAddT * midAddT > v){ | |
double_v = mid; | |
break; | |
} | |
low = low+t; | |
} | |
} | |
return double_v; | |
} | |
int main(int argc, char *argv[]) { | |
printf("%.16f",ssqrt(50000, 0.0001)); | |
return 0; | |
} |
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// Created by zscself on 2016/12/20. | |
#include <stdio.h> | |
double newton(double x,double a){ | |
double fx = x*x - a; | |
double fxD = 2*x; | |
double f = x-fx/fxD; | |
return f; | |
} | |
double ssqrt(int v,double t){ | |
double f,dv; | |
f = dv = (double) v; | |
while (1) { | |
dv = newton(dv,f); | |
if(dv * dv < f && (dv+t)*(dv+t)>f){ | |
break; | |
} | |
if(dv * dv > f && (dv-t)*(dv-t)<f){ | |
break; | |
} | |
} | |
return dv; | |
} | |
int main(int argc, char *argv[]) { | |
printf("%.16f",ssqrt(50000, 0.0001)); | |
} |
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