23 lines
692 B
C
23 lines
692 B
C
#include <stdio.h>
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#define for_i(i, range, inner) \
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{ \
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int i; \
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for (i = 0; i < range; i++) \
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inner; \
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}
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int main() {
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int n, cnt;
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scanf("%d", &n);
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for_i(i, n + 1, {
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int a = i;
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while (a != 0) {
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if (a % 10 == 2) {
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cnt++;
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}
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a /= 10;
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}
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});
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printf("%d", cnt);
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return 0;
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} |