可能 $\ldots$ 并不需要快读？
by _d_h_f @ 2024-04-11 19:29:28
~~我甚至 cin 都过了~~
by _d_h_f @ 2024-04-11 19:34:27
@[_d_h_f](/user/1057109) 666，但我就是想知道为什么有负数
by 20121202Tzy @ 2024-04-11 19:55:08
@[20121202Tzy](/user/1020835) 给个代码找下原因
by _d_h_f @ 2024-04-12 11:57:02
@[_d_h_f](/user/1057109)
0pts
```cpp
#include <iostream>
using namespace std;
int n, m, x, a[1000001];
int read()
{
int s = 0;
char c = getchar();
while (c >= '0' && c <= '9')
{
s = s * 10 + c - '0';
c = getchar();
}
return s;
}
void write(int n)
{
if (n < 0)
{
putchar('-');
n = -n;
}
if (n >= 10) write(n / 10);
putchar(n % 10 + '0');
}
int find(int x)
{
int l = 1, r = n + 1;
while (l < r)
{
int mid = l + (r - l) / 2;
if (a[mid] >= x) r = mid;
else l = mid + 1;
}
if (a[l] == x) return l;
else return -1;
}
int main()
{
n = read(), m = read();
for (int i = 1; i <= n; i++) a[i] = read();
while (m--)
{
x = read();
write(find(x));
putchar(' ');
}
return 0;
}
```````
100pts
```cpp#include <iostream>
using namespace std;
int n, m, x, a[1000001];
int read()
{
int s = 0, w = 1;
char c = getchar();
while (c < '0' || c > '9')
{
if (c == '-') w = -1;
c = getchar();
}
while (c >= '0' && c <= '9')
{
s = s * 10 + c - '0';
c = getchar();
}
return s;
}
void write(int n)
{
if (n < 0)
{
putchar('-');
n = -n;
}
if (n >= 10) write(n / 10);
putchar(n % 10 + '0');
}
int find(int x)
{
int l = 1, r = n + 1, mid;
while (l < r)
{
mid = l + (r - l) / 2;
if (a[mid] >= x) r = mid;
else l = mid + 1;
}
if (a[l] == x) return l;
return -1;
}
int main()
{
n = read(), m = read();
for (int i = 1; i <= n; i++) a[i] = read();
while (m--)
{
x = read();
write(find(x));
putchar(' ');
}
return 0;
}
``````
by 20121202Tzy @ 2024-04-12 14:19:31