28 lines
436 B
C
28 lines
436 B
C
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#include "clapack.h"
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integer pow_ii(integer *ap, integer *bp)
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{
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integer pow, x, n;
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unsigned long u;
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x = *ap;
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n = *bp;
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if (n <= 0) {
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if (n == 0 || x == 1)
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return 1;
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return x != -1 ? 0 : (n & 1) ? -1 : 1;
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}
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u = n;
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for(pow = 1; ; )
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{
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if(u & 01)
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pow *= x;
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if(u >>= 1)
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x *= x;
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else
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break;
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}
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return(pow);
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}
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