1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
|
// 946. Validate Stack Sequences
#include "leetcode.h"
/*
* given two integer arrays 'pushed' & 'popped' each with distinct
* values, return true if this could have been the result of a sequence
* of push and pop operations on an initially empty stack, or false otherwise
*/
class Solution {
public:
bool validateStackSequences(vector<int> &pushed, vector<int> &popped) {
stack<int> s;
int i = 0;
for (int x : pushed) {
s.push(x);
while (s.size() && s.top() == popped[i]) {
s.pop();
i++;
}
}
return !s.size();
}
};
int main() {
Solution obj;
vector<int> pushed = {1, 2, 3, 4, 5};
vector<int> p1 = {4, 5, 3, 2, 1}, p2 = {4, 3, 5, 1, 2};
printf("%d\n", obj.validateStackSequences(pushed, p1)); // expect: 1
printf("%d\n", obj.validateStackSequences(pushed, p2)); // expect: 0
}
|