fix

yosupo06 · yosupo06 · commit 24b7295e59b5 · 2021-07-19T14:28:32.000+09:00
diff --git a/atcoder/convolution.hpp b/atcoder/convolution.hpp
@@ -132,7 +132,7 @@ void butterfly_inv(std::vector<mint>& a) {
                         irot.val();
                     ;
                 }
-                irot *= info.irate2[bsf(~(unsigned int)(s))];
+                if (s + 1 != (1 << len)) irot *= info.irate2[bsf(~(unsigned int)(s))];
             }
             len--;
         } else {
@@ -163,7 +163,7 @@ void butterfly_inv(std::vector<mint>& a) {
                         (a0 + (mint::mod() - a1) + (mint::mod() - a2na3iimag)) *
                         irot3.val();
                 }
-                irot *= info.irate3[bsf(~(unsigned int)(s))];
+                if (s + 1 != (1 << len)) irot *= info.irate3[bsf(~(unsigned int)(s))];
             }
             len -= 2;
         }

Original file line number	Diff line number	Diff line change
`@@ -132,7 +132,7 @@ void butterfly_inv(std::vector<mint>& a) {`
`132`	`132`	`irot.val();`
`133`	`133`	`;`
`134`	`134`	`}`
`135`		`- irot *= info.irate2[bsf(~(unsigned int)(s))];`
	`135`	`+ if (s + 1 != (1 << len)) irot *= info.irate2[bsf(~(unsigned int)(s))];`
`136`	`136`	`}`
`137`	`137`	`len--;`
`138`	`138`	`} else {`
`@@ -163,7 +163,7 @@ void butterfly_inv(std::vector<mint>& a) {`
`163`	`163`	`(a0 + (mint::mod() - a1) + (mint::mod() - a2na3iimag)) *`
`164`	`164`	`irot3.val();`
`165`	`165`	`}`
`166`		`- irot *= info.irate3[bsf(~(unsigned int)(s))];`
	`166`	`+ if (s + 1 != (1 << len)) irot *= info.irate3[bsf(~(unsigned int)(s))];`
`167`	`167`	`}`
`168`	`168`	`len -= 2;`
`169`	`169`	`}`