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https://github.com/xlucn/PAT.git
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47 lines
1.4 KiB
C
47 lines
1.4 KiB
C
#include <stdio.h>
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#define BLANK -1
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#define SIGNED -2
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#define SINGLE -3
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int main()
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{
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int couple[100000], count = 0, N, M, ID1, ID2;
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for(int i = 0; i < 100000; i++)
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couple[i] = BLANK;
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/* Read 'couple-list', every pair of 'index' and 'value' are a couple. */
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scanf("%d", &N);
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for(int i = 0; i < N; i++)
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{
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scanf("%d %d", &ID1, &ID2);
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couple[ID1] = ID2;
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couple[ID2] = ID1;
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}
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scanf("%d", &M);
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for(int i = 0; i < M; i++) /* Read guest list. */
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{
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scanf("%d", &ID1);
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if(couple[ID1] >= 0) /* If one has a mate */
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couple[ID1] = SIGNED; /* set SIGNED */
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else /* Else: not in the 'couple-list' */
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couple[ID1] = SINGLE, count++; /* set SINGLE */
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}
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/* If couple[ID] is >= 0 (but not signed) but couple[couple[ID]] == SIGNED
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* (signed in), this means 'ID' didn't come but his/her mate did.
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* So his/her mate is alone in the party, set to SINGLE. */
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for(int i = 0; i < 100000; i++)
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if(couple[i] >= 0 && couple[couple[i]] == SIGNED)
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couple[couple[i]] = SINGLE, count++;
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/* Those whose value is SINGLE is either a bachelor or came alone */
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printf("%d\n", count);
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for(int i = 0; i < 100000; i++)
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if(couple[i] == SINGLE)
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printf("%05d%c", i, --count ? ' ' : '\0');
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return 0;
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}
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