回答編集履歴
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rewrite answer
answer
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@@ -1,18 +1,19 @@
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整数`n`の20%、つまり`n / 5`の切り上げは`(n + 4) / 5`(全てint型で計算)で求まります。
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```
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```
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#include <assert.h>
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#include <stdio.h>
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int ceil20up(int n)
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{
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assert(0 <= n);
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int r = (n + 4) / 5; // ceil(n * 20%)
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return
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return n + r;
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}
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int main()
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{
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for (int i = 1; i <= 100; i++)
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printf("%d->%d\n", i, ceil20up(i));
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printf("%d -> %.1f -> %d\n", i, i * 1.2, ceil20up(i));
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}
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```
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