火车进站,模拟一个栈的操作,额外的栈操作,查看能否依照规定顺序出栈。
数据量非常少,故此题目非常easyAC。
直接使用数组模拟就好。
#include <stdio.h>
const int MAX_N = 10;
char inOrder[MAX_N], outOrder[MAX_N], stk[MAX_N];
bool rs[MAX_N<<2];
int n;
int main()
{
while (scanf("%d", &n) != EOF)
{
scanf("%s %s", inOrder, outOrder);
int j = 0, out = 0, i = 0, st = 0;
bool possible = true;
while (possible && !(st == 0 && out == n))
{
for (; i < n && inOrder[i] != outOrder[out]; i++)
{
rs[j++] = true;
stk[st++] = inOrder[i];
}//push in
i++;//Watch out: don't forget while inOrder[i]==outOrder[out]!
rs[j++] = true;
rs[j++] = false;
out++;
while (st > 0 && stk[st-1] == outOrder[out])
{
st--; out++;
rs[j++] = false;
}//pop back
int k = 0;//check possible
for (; k < st && stk[k] != outOrder[out]; k++);
if (k < st) possible = false;
}
if (possible)
{
puts("Yes.");
for (int i = 0; i < j; i++)
{
if (rs[i]) puts("in");
else puts("out");
}
}
else puts("No.");
puts("FINISH");
}
return 0;
}
解法二:
#include <stdio.h>
const int MAX_N = 10;
char inOrder[MAX_N], outOrder[MAX_N], stk[MAX_N];
bool rs[MAX_N<<2];
int n;
int main()
{
while (scanf("%d", &n) != EOF)
{
scanf("%s %s", inOrder, outOrder);
int j = 0, out = 0, i = 0, st = 0;
while (i<n && !(st == 0 && out == n))
{
for (; i < n && inOrder[i] != outOrder[out]; i++)
{
rs[j++] = true;
stk[st++] = inOrder[i];
}//push in
i++;//Watch out: don't forget while inOrder[i]==outOrder[out]!
rs[j++] = true;
rs[j++] = false;
out++;
while (st > 0 && stk[st-1] == outOrder[out])
{
st--; out++;
rs[j++] = false;
}//pop back
}
if (st == 0 && out == n)
{
puts("Yes.");
for (int i = 0; i < j; i++)
{
if (rs[i]) puts("in");
else puts("out");
}
}
else puts("No.");
puts("FINISH");
}
return 0;
}