87 lines
1.9 KiB
C
87 lines
1.9 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <math.h>
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#define f(x) (x+sin(x)-1)
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//#define f(x) ((x)*(x))
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//#define f(x) ((x)*exp(x)*(x)*exp(x))
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int main() {
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int count = 1000 , i=0;
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double precision = 1e-10 ;
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//num為選擇解哪個方程式
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double mid , lower=-20 , upper=10, num=2;
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printf("迭代\t區間\t\t\t\t中間值\n");
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printf("-------+-------------------------------+-------------\n");
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printf("%.10f\n",f(num));
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//解為0.510973
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if(f(num)==(num+sin(num)-1)){
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while (upper - lower > precision && i < count ) {
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mid = (lower + upper) / 2.0;
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printf("#%d\t[%.10f,%.10f]\t解=%.10f\n",i+1,lower,upper,mid);
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if (fabs(f(mid)) < precision) {
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break;
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}
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i++;
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if ( f(mid) * f(lower) < 0) {
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upper = mid;
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} else {
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lower = mid;
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}
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}
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}
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//解為0
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if(f(num)==(num*num)){
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while (upper - lower > precision && i < count ) {
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mid = (lower + upper) / 2.0;
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printf("#%d\t[%.10f,%.10f]\t解=%.10f\n",i+1,lower,upper,mid);
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// printf("\nf(mid)=%.10f, f(lower)=%.10f, f(upper)=%.10f\n",f(mid),f(lower),f(upper));
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if (fabs(f(mid)) < precision) {
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break;
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}
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i++;
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if ( f(mid) > precision) {
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if(mid>0){
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upper = mid;
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} else if(mid<0){
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lower = mid;
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}
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}
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}
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}
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//唯一解為0,趨近解所有為小於-5的負數
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if(f(num)==((num)*exp(num)*(num)*exp(num))){
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while (upper - lower > precision && i < count ) {
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mid = (lower + upper) / 2.0;
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printf("#%d\t[%.10f,%.10f]\t解=%.10f\n",i+1,lower,upper,mid);
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// printf("mid=%.10f,f(mid)=%.10f\n",mid,f(mid));
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if (fabs(f(mid)) < precision) {
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break;
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}
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i++;
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if ( f(mid) > precision) {
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if(mid>0){
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upper = mid;
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} else if(mid<0){
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lower = mid;
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}
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}
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}
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}
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printf("\n方程式的解為%f\n",mid);
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printf("\n驗算結果f(mid)的值為%f",f(mid));
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return 0;
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}
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