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124 lines
3.2 KiB
C
124 lines
3.2 KiB
C
/*
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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* Neither the name of "The Computer Language Benchmarks Game" nor the
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name of "The Computer Language Shootout Benchmarks" nor the names of
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its contributors may be used to endorse or promote products derived
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from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE.
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*/
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/* The Computer Language Benchmarks Game
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http://shootout.alioth.debian.org/
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contributed by Paolo Bonzini & Sean Bartlett
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modified by Michael Mellor
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <gmp.h>
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static mpz_t numer, accum, denom, tmp1, tmp2;
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static int extract_digit()
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{
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if (mpz_cmp(numer, accum) > 0)
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return -1;
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/* Compute (numer * 3 + accum) / denom */
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mpz_mul_2exp(tmp1, numer, 1);
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mpz_add(tmp1, tmp1, numer);
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mpz_add(tmp1, tmp1, accum);
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mpz_fdiv_qr(tmp1, tmp2, tmp1, denom);
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/* Now, if (numer * 4 + accum) % denom... */
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mpz_add(tmp2, tmp2, numer);
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/* ... is normalized, then the two divisions have the same result. */
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if (mpz_cmp(tmp2, denom) >= 0)
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return -1;
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return mpz_get_ui(tmp1);
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}
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static void next_term(unsigned int k)
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{
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unsigned int y2 = k*2 + 1;
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mpz_mul_2exp(tmp1, numer, 1);
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mpz_add(accum, accum, tmp1);
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mpz_mul_ui(accum, accum, y2);
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mpz_mul_ui(numer, numer, k);
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mpz_mul_ui(denom, denom, y2);
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}
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static void eliminate_digit(unsigned int d)
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{
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mpz_submul_ui(accum, denom, d);
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mpz_mul_ui(accum, accum, 10);
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mpz_mul_ui(numer, numer, 10);
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}
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static void pidigits(unsigned int n)
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{
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int d;
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unsigned int i = 0, k = 0, m;
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mpz_init(tmp1);
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mpz_init(tmp2);
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mpz_init_set_ui(numer, 1);
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mpz_init_set_ui(accum, 0);
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mpz_init_set_ui(denom, 1);
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for(;;)
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{
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do {
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k++;
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next_term(k);
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d = extract_digit();
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} while(d == -1);
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putchar(d + '0');
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i++;
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m = i%10;
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if(m == 0)
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printf("\t:%d\n", i);
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if(i >= n)
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break;
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eliminate_digit(d);
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}
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if(m) {
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m = 10 - m;
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while(m--)
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putchar(' ');
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printf("\t:%d\n", n);
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}
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}
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int main(int argc, char **argv)
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{
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pidigits(argc > 1 ? atoi(argv[1]) : 27);
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return 0;
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}
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