49 lines
519 B
C
49 lines
519 B
C
#include <stdio.h>
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#include <stdlib.h>
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#include <time.h>
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#include <math.h>
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// !素数判断的简化版本
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int sushu(int x)
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{
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int ret = 1;
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if (x <= 1)
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{
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ret = 0;
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}
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int i;
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if (x == 2 || (x % 2 == 0 && x != 2)) // 排除偶数
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{
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ret = 0;
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}
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for (i = 3; i < (int)sqrt(x)+1; i += 2)
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{
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if (x % i == 0)
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{
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ret = 0;
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break;
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}
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}
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return ret;
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}
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int main()
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{
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int x;
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printf("输入数字：");
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scanf("%d", &x);
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if (sushu(x))
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{
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printf("%d是素数\n", x);
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}
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else
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{
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printf("%d不是素数\n", x);
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}
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return 0;
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} |