Data_Structure/作業/unit1/binary-search-solves-equation.c

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2025-01-20 21:25:33 +08:00
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#define f(x) (x+sin(x)-1)
//#define f(x) ((x)*(x))
//#define f(x) ((x)*exp(x)*(x)*exp(x))
int main() {
int count = 1000 , i=0;
double precision = 1e-10 ;
//num<75><6D><EFBFBD><EFBFBD><EFBFBD>ܸѭ<DCB8><D1AD>Ӥ<EFBFBD><D3A4>{<7B><>
double mid , lower=-20 , upper=10, num=2;
printf("<EFBFBD><EFBFBD><EFBFBD>N\t<EFBFBD>϶<EFBFBD>\t\t\t\t<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>\n");
printf("-------+-------------------------------+-------------\n");
printf("%.10f\n",f(num));
//<2F>Ѭ<EFBFBD>0.510973
if(f(num)==(num+sin(num)-1)){
while (upper - lower > precision && i < count ) {
mid = (lower + upper) / 2.0;
printf("#%d\t[%.10f,%.10f]\t<EFBFBD><EFBFBD>=%.10f\n",i+1,lower,upper,mid);
if (fabs(f(mid)) < precision) {
break;
}
i++;
if ( f(mid) * f(lower) < 0) {
upper = mid;
} else {
lower = mid;
}
}
}
//<2F>Ѭ<EFBFBD>0
if(f(num)==(num*num)){
while (upper - lower > precision && i < count ) {
mid = (lower + upper) / 2.0;
printf("#%d\t[%.10f,%.10f]\t<EFBFBD><EFBFBD>=%.10f\n",i+1,lower,upper,mid);
// printf("\nf(mid)=%.10f, f(lower)=%.10f, f(upper)=%.10f\n",f(mid),f(lower),f(upper));
if (fabs(f(mid)) < precision) {
break;
}
i++;
if ( f(mid) > precision) {
if(mid>0){
upper = mid;
} else if(mid<0){
lower = mid;
}
}
}
}
//<2F>ߤ@<40>Ѭ<EFBFBD>0,<2C>ͪ<EFBFBD><CDAA>ѩҦ<D1A9><D2A6><EFBFBD><EFBFBD>p<EFBFBD><70>-5<><35><EFBFBD>t<EFBFBD><74>
if(f(num)==((num)*exp(num)*(num)*exp(num))){
while (upper - lower > precision && i < count ) {
mid = (lower + upper) / 2.0;
printf("#%d\t[%.10f,%.10f]\t<EFBFBD><EFBFBD>=%.10f\n",i+1,lower,upper,mid);
// printf("mid=%.10f,f(mid)=%.10f\n",mid,f(mid));
if (fabs(f(mid)) < precision) {
break;
}
i++;
if ( f(mid) > precision) {
if(mid>0){
upper = mid;
} else if(mid<0){
lower = mid;
}
}
}
}
printf("\n<EFBFBD><EFBFBD><EFBFBD>{<7B><><EFBFBD><EFBFBD><EFBFBD>Ѭ<EFBFBD>%f\n",mid);
printf("\n<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Gf(mid)<29><><EFBFBD>Ȭ<EFBFBD>%f",f(mid));
return 0;
}