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@caa45040(caa45040)

小規模回路マイコンでの1/xを考える(2)(表引き)(主に距離センサー)

Last updated at Posted at 2025-07-23

目的

  • 1÷なんか=距離

  • 答え(解)の範囲が50から800

  • エラーは、0

  • 割る数が2000を超えると結果は、不定

  • 7ffは、コアダンプ対策のマスク

  • 浮動小数点数的には、1➗0.02=50

  • 十進数固定小数点五桁

  • 1➗x,次は、1より小さいは、ほぼ、直線なので一次関数で近似してみる(そのうち

  • 微分: 1➗x,f(x)=1➗(x ✖️ x) (ようは、曲線の傾きの事

プログラム

オンラインコンパイラ



unsigned short qq[] = {
0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,800,793,787,781,775,
769,763,757,751,746,740,735,729,724,719,
714,709,704,699,694,689,684,680,675,671,
666,662,657,653,649,645,641,636,632,628,
625,621,617,613,609,606,602,598,595,591,
588,584,581,578,574,571,568,564,561,558,
555,552,549,546,543,540,537,534,531,529,
526,523,520,518,515,512,510,507,505,502,
500,497,495,492,490,487,485,483,480,478,
476,473,471,469,467,465,462,460,458,456,
454,452,450,448,446,444,442,440,438,436,
434,432,431,429,427,425,423,421,420,418,
416,414,413,411,409,408,406,404,403,401,
400,398,396,395,393,392,390,389,387,386,
384,383,381,380,378,377,375,374,373,371,
370,369,367,366,364,363,362,361,359,358,
357,355,354,353,352,350,349,348,347,346,
344,343,342,341,340,338,337,336,335,334,
333,332,331,330,328,327,326,325,324,323,
322,321,320,319,318,317,316,315,314,313,
312,311,310,309,308,307,306,305,304,303,
303,302,301,300,299,298,297,296,295,294,
294,293,292,291,290,289,289,288,287,286,
285,284,284,283,282,281,280,280,279,278,
277,277,276,275,274,273,273,272,271,271,
270,269,268,268,267,266,265,265,264,263,
263,262,261,261,260,259,259,258,257,257,
256,255,255,254,253,253,252,251,251,250,
250,249,248,248,247,246,246,245,245,244,
243,243,242,242,241,240,240,239,239,238,
238,237,236,236,235,235,234,234,233,233,
232,232,231,230,230,229,229,228,228,227,
227,226,226,225,225,224,224,223,223,222,
222,221,221,220,220,219,219,218,218,217,
217,216,216,215,215,215,214,214,213,213,
212,212,211,211,210,210,210,209,209,208,
208,207,207,207,206,206,205,205,204,204,
204,203,203,202,202,202,201,201,200,200,
200,199,199,198,198,198,197,197,196,196,
196,195,195,194,194,194,193,193,193,192,
192,191,191,191,190,190,190,189,189,189,
188,188,187,187,187,186,186,186,185,185,
185,184,184,184,183,183,183,182,182,182,
181,181,181,180,180,180,179,179,179,178,
178,178,177,177,177,176,176,176,176,175,
175,175,174,174,174,173,173,173,173,172,
172,172,171,171,171,170,170,170,170,169,
169,169,168,168,168,168,167,167,167,166,
166,166,166,165,165,165,165,164,164,164,
163,163,163,163,162,162,162,162,161,161,
161,161,160,160,160,160,159,159,159,158,
158,158,158,157,157,157,157,156,156,156,
156,156,155,155,155,155,154,154,154,154,
153,153,153,153,152,152,152,152,151,151,
151,151,151,150,150,150,150,149,149,149,
149,149,148,148,148,148,147,147,147,147,
147,146,146,146,146,145,145,145,145,145,
144,144,144,144,144,143,143,143,143,143,
142,142,142,142,142,141,141,141,141,141,
140,140,140,140,140,139,139,139,139,139,
138,138,138,138,138,137,137,137,137,137,
136,136,136,136,136,136,135,135,135,135,
135,134,134,134,134,134,134,133,133,133,
133,133,132,132,132,132,132,132,131,131,
131,131,131,131,130,130,130,130,130,130,
129,129,129,129,129,129,128,128,128,128,
128,128,127,127,127,127,127,127,126,126,
126,126,126,126,125,125,125,125,125,125,
125,124,124,124,124,124,124,123,123,123,
123,123,123,123,122,122,122,122,122,122,
121,121,121,121,121,121,121,120,120,120,
120,120,120,120,119,119,119,119,119,119,
119,118,118,118,118,118,118,118,117,117,
117,117,117,117,117,116,116,116,116,116,
116,116,116,115,115,115,115,115,115,115,
114,114,114,114,114,114,114,114,113,113,
113,113,113,113,113,112,112,112,112,112,
112,112,112,111,111,111,111,111,111,111,
111,110,110,110,110,110,110,110,110,110,
109,109,109,109,109,109,109,109,108,108,
108,108,108,108,108,108,107,107,107,107,
107,107,107,107,107,106,106,106,106,106,
106,106,106,106,105,105,105,105,105,105,
105,105,105,104,104,104,104,104,104,104,
104,104,103,103,103,103,103,103,103,103,
103,102,102,102,102,102,102,102,102,102,
102,101,101,101,101,101,101,101,101,101,
101,100,100,100,100,100,100,100,100,100,
100,99,99,99,99,99,99,99,99,99,
99,98,98,98,98,98,98,98,98,98,
98,97,97,97,97,97,97,97,97,97,
97,96,96,96,96,96,96,96,96,96,
96,96,95,95,95,95,95,95,95,95,
95,95,95,94,94,94,94,94,94,94,
94,94,94,94,93,93,93,93,93,93,
93,93,93,93,93,93,92,92,92,92,
92,92,92,92,92,92,92,91,91,91,
91,91,91,91,91,91,91,91,91,90,
90,90,90,90,90,90,90,90,90,90,
90,90,89,89,89,89,89,89,89,89,
89,89,89,89,88,88,88,88,88,88,
88,88,88,88,88,88,88,87,87,87,
87,87,87,87,87,87,87,87,87,87,
86,86,86,86,86,86,86,86,86,86,
86,86,86,85,85,85,85,85,85,85,
85,85,85,85,85,85,85,84,84,84,
84,84,84,84,84,84,84,84,84,84,
84,83,83,83,83,83,83,83,83,83,
83,83,83,83,83,82,82,82,82,82,
82,82,82,82,82,82,82,82,82,82,
81,81,81,81,81,81,81,81,81,81,
81,81,81,81,81,80,80,80,80,80,
80,80,80,80,80,80,80,80,80,80,
80,79,79,79,79,79,79,79,79,79,
79,79,79,79,79,79,78,78,78,78,
78,78,78,78,78,78,78,78,78,78,
78,78,78,77,77,77,77,77,77,77,
77,77,77,77,77,77,77,77,77,76,
76,76,76,76,76,76,76,76,76,76,
76,76,76,76,76,76,75,75,75,75,
75,75,75,75,75,75,75,75,75,75,
75,75,75,75,74,74,74,74,74,74,
74,74,74,74,74,74,74,74,74,74,
74,74,73,73,73,73,73,73,73,73,
73,73,73,73,73,73,73,73,73,73,
72,72,72,72,72,72,72,72,72,72,
72,72,72,72,72,72,72,72,72,71,
71,71,71,71,71,71,71,71,71,71,
71,71,71,71,71,71,71,71,71,70,
70,70,70,70,70,70,70,70,70,70,
70,70,70,70,70,70,70,70,70,69,
69,69,69,69,69,69,69,69,69,69,
69,69,69,69,69,69,69,69,69,69,
68,68,68,68,68,68,68,68,68,68,
68,68,68,68,68,68,68,68,68,68,
68,67,67,67,67,67,67,67,67,67,
67,67,67,67,67,67,67,67,67,67,
67,67,67,66,66,66,66,66,66,66,
66,66,66,66,66,66,66,66,66,66,
66,66,66,66,66,66,65,65,65,65,
65,65,65,65,65,65,65,65,65,65,
65,65,65,65,65,65,65,65,65,64,
64,64,64,64,64,64,64,64,64,64,
64,64,64,64,64,64,64,64,64,64,
64,64,64,63,63,63,63,63,63,63,
63,63,63,63,63,63,63,63,63,63,
63,63,63,63,63,63,63,63,62,62,
62,62,62,62,62,62,62,62,62,62,
62,62,62,62,62,62,62,62,62,62,
62,62,62,61,61,61,61,61,61,61,
61,61,61,61,61,61,61,61,61,61,
61,61,61,61,61,61,61,61,61,61,
60,60,60,60,60,60,60,60,60,60,
60,60,60,60,60,60,60,60,60,60,
60,60,60,60,60,60,60,59,59,59,
59,59,59,59,59,59,59,59,59,59,
59,59,59,59,59,59,59,59,59,59,
59,59,59,59,59,58,58,58,58,58,
58,58,58,58,58,58,58,58,58,58,
58,58,58,58,58,58,58,58,58,58,
58,58,58,58,58,57,57,57,57,57,
57,57,57,57,57,57,57,57,57,57,
57,57,57,57,57,57,57,57,57,57,
57,57,57,57,57,56,56,56,56,56,
56,56,56,56,56,56,56,56,56,56,
56,56,56,56,56,56,56,56,56,56,
56,56,56,56,56,56,55,55,55,55,
55,55,55,55,55,55,55,55,55,55,
55,55,55,55,55,55,55,55,55,55,
55,55,55,55,55,55,55,55,55,54,
54,54,54,54,54,54,54,54,54,54,
54,54,54,54,54,54,54,54,54,54,
54,54,54,54,54,54,54,54,54,54,
54,54,53,53,53,53,53,53,53,53,
53,53,53,53,53,53,53,53,53,53,
53,53,53,53,53,53,53,53,53,53,
53,53,53,53,53,53,53,52,52,52,
52,52,52,52,52,52,52,52,52,52,
52,52,52,52,52,52,52,52,52,52,
52,52,52,52,52,52,52,52,52,52,
52,52,52,52,51,51,51,51,51,51,
51,51,51,51,51,51,51,51,51,51,
51,51,51,51,51,51,51,51,51,51,
51,51,51,51,51,51,51,51,51,51,
51,50,50,50,50,50,50,50,50,50,
50,50,50,50,50,50,50,50,50,50,
50,50,50,50,50,50,50,50,50,50,
50,50,50,50,50,50,50,50,50,50,
50,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0
};

#include <iostream>
using namespace std;
int main(void){
    // Your code here!
    
    int a;
    
    a = 125;
    printf("100000/%d=%d\n",a,qq[a & 0x7ff]);

    a = 2000;
    printf("100000/%d=%d\n",a,qq[a & 0x7ff]);
    
    
}




100000/125=800
100000/2000=50
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