回答編集履歴
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訂正
answer
CHANGED
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@@ -1,1 +1,20 @@
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struct tm → time_t → struct tmと変換すれば、よろしくやってくれます。
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```c
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1
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-
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3
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#include <time.h>
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5
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void yesterday(int *y, int *m, int *d)
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{
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7
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struct tm st = {0};
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8
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time_t tt;
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9
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10
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st.tm_year = *y - 1900;
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11
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st.tm_mon = *m - 1;
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12
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st.tm_mday = *d - 1; /* 1日前の日付を設定 */
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14
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tt = mktime(&st);
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15
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st = *localtime(&tt);
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*y = st.tm_year + 1900;
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*m = st.tm_mon + 1;
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18
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*d = st.tm_mday;
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19
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}
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20
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```
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