28 lines
458 B
C
28 lines
458 B
C
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#include <stdio.h>
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int n[30],number;
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long long count = 0;
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int tdo(int deep);
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int main(void){
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scanf("%d",&number);
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tdo(1);
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printf("%lld\n",count);
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return 0;
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}
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int tdo(int deep){
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int i,k;
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for(i = 1; i <= 2; i++){
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n[deep] = i;
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if(deep > 2)
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if(n[deep] == 2 && n[deep-1] == 2 && n[deep-2] == 2){
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int max = 1;
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for(k = 0; k < number-deep; k++) max *= 2;
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count += max;
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return 0;
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}
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if(deep < number)
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tdo(deep+1);
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}
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return 0;
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}
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