Mr. Frog learned a basic data structure recently, which is called stack.There are some basic operations of stack：
∙ 1 nand 1 = 0
Because Mr. Frog needs to do some tiny contributions now, you should help him finish this data structure： print the answer to each QUERY, or tell him that is invalid.
∙ 1 nand 1 = 0
Because Mr. Frog needs to do some tiny contributions now, you should help him finish this data structure： print the answer to each QUERY, or tell him that is invalid.
InputThe first line contains only one integer T (Sample Input
2 8 PUSH 1 QUERY PUSH 0 REVERSE QUERY POP POP QUERY 3 PUSH 0 REVERSE QUERY
Sample Output
Case #1:
1
1
Invalid.
Case #2:
0
Hint
In the first sample： during the first query, the stack contains only one element 1, so the answer is 1. then in the second query, the stack contains 0, l
(from bottom to top), so the answer to the second is also 1. In the third query, there is no element in the stack, so you should output Invalid.
给一个栈.有push,pop,query ,reverse这些操作,
对于每个询问输出这个栈从栈顶到底进行题目给的这个运算后的结果;
∙ 1 nand 1 = 0
组队训练赛的时候这题我直接扔给队友写的
队友写的自闭了 不过最后还是出来了
自己赛后补题 补到自闭
我不适合写模拟
我写了很久 尽量的简化了 模拟过程
1 #include <cstdio> 2 #include <cstring> 3 #include <queue> 4 #include <cmath> 5 #include <algorithm> 6 #include <set> 7 #include <iostream> 8 #include <map> 9 #include <stack> 10 #include <string> 11 #include <vector> 12 #define pi acos(-1.0) 13 #define eps 1e-6 14 #define fi first 15 #define se second 16 #define lson l,m,rt<<1 17 #define rson m+1,r,rt<<1|1 18 #define bug printf("******\n") 19 #define mem(a,b) memset(a,b,sizeof(a)) 20 #define fuck(x) cout<<"["<<x<<"]"<<endl 21 #define f(a) a*a 22 #define sf(n) scanf("%d", &n) 23 #define sff(a,b) scanf("%d %d", &a, &b) 24 #define sfff(a,b,c) scanf("%d %d %d", &a, &b, &c) 25 #define sffff(a,b,c,d) scanf("%d %d %d %d", &a, &b, &c, &d) 26 #define pf printf 27 #define FRE(i,a,b) for(i = a; i <= b; i++) 28 #define FREE(i,a,b) for(i = a; i >= b; i--) 29 #define FRL(i,a,b) for(i = a; i < b; i++) 30 #define FRLL(i,a,b) for(i = a; i > b; i--) 31 #define FIN freopen("DATA.txt","r",stdin) 32 #define gcd(a,b) __gcd(a,b) 33 #define lowbit(x) x&-x 34 #pragma comment (linker,"/STACK:102400000,102400000") 35 using namespace std; 36 typedef long long LL; 37 typedef unsigned long long ULL; 38 const int INF = 0x7fffffff; 39 const int mod = 1e9 + 7; 40 const int maxn = 4e5 + 10; 41 int t, n, a[maxn], L, R, cas = 1, x; 42 char s[10]; 43 multiset<int>st; 44 multiset<int>::iterator it; 45 int main() { 46 // FIN; 47 sf(t); 48 while(t--) { 49 st.clear(); 50 L = 2e5, R = 2e5; 51 int flag = 1; 52 sf(n); 53 printf("Case #%d:\n", cas++); 54 for (int i = 0 ; i < n ; i++) { 55 scanf("%s", s); 56 if (s[0] == 'Q') { 57 if (L == R) printf("Invalid.\n"); 58 else if (st.empty()) printf("%d\n",(R-L)%2); 59 else { 60 if (flag) { 61 //fuck((*st.begin()) - L); 62 printf("%d\n", (((*st.begin()) - L) + (*st.begin() != R - 1)) % 2); 63 } else { 64 it=st.end(); 65 it--; 66 // fuck(L); 67 printf("%d\n", ((R - (*it))-1 + (*it != L)) % 2); 68 } 69 } 70 } 71 if (s[0] == 'P' && s[1] == 'U') { 72 sf(x); 73 if (flag) a[R++] = x; 74 else a[--L] = x; 75 if (!x) { 76 if (flag) st.insert(R - 1); 77 else st.insert(L); 78 } 79 } 80 if (s[0] == 'P' && s[1] == 'O') { 81 if (L == R) continue; 82 if (flag) { 83 if(!a[R - 1]) st.erase(R - 1); 84 R--; 85 } else { 86 if (!a[L]) st.erase(L); 87 L++; 88 } 89 } 90 if (s[0] == 'R') flag ^= 1; 91 } 92 } 93 return 0; 94 }