60 lines
1.2 KiB
C
60 lines
1.2 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*x*x-2*x*x-x+2)
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//#define f(x) (x*x-100)
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#define f(x) (3*x*x*x*x+9*x*x*x-198*x*x+156*x+360)
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void binary_search ( int *ans){
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int count = 1000 , i=0;
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double mid , lower=-15 , upper=20;
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while ((f(mid)) != 0 && i < count ) {
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mid = (lower + upper) / 2.0;
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printf("#%d\t[%f,%f]\t解=%f\n",i+1,lower,upper,mid);
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if (fabs(f(mid)) == 0) {
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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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}*ans = mid;
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}
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void Exhaustive(int a, int b, int *ans, int *count) {
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*count = 0;
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int i;
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for (i = a; i <= b; i++) {
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if (f(i) == 0) {
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ans[*count] = i;
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(*count)++;
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}
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}
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}
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int main() {
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int i , x , lower=-200 , upper=200 ;
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int ans[10];
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int *count;
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Exhaustive(lower,upper,ans,&count);
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if (count > 0) {
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printf("*** 解多項式之整數根 ***\n");
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printf("\n方程式p(x)= 3^4+9x^3-198x^2+156+360\n");
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printf("\n解得整數根為");
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for (i = 0; i < count; i++) {
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printf(" %d ", ans[i]);
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}
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} else {
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printf("在給定範圍內沒有找到整數解。\n");
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}
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return 0;
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}
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