校验出栈顺序
2017-05-16 本文已影响91人
senninha
给定入栈顺序,给出一组出栈顺序,判断是否满足条件
public static boolean isOutStack(int[] inBound,int[] outBound){
Stack<Integer> stack = new Stack<Integer>();
//进栈的下标
int in = 0;
//出栈的下标
int out = 0;
//当出栈的下标到5时,循环停止
while(out != outBound.length){
//当进栈为完时
if(in < inBound.length){
//如果进的那个等于出的那个,直接下标各自+1
if(inBound[in] == outBound[out]){
out++;
in++;
//如果不相等,这时候如果栈不为空,要考虑当前出栈的元素与栈顶的元素是否相同
}else if(stack.size() > 0){
int tem = stack.pop();
//若相同,则把它出栈,出栈下标+1
if(tem == outBound[out]){
out++;
//否则,入栈当前元素,入栈+1
}else{
stack.push(tem);
stack.push(inBound[in]);
in++;
}
//栈为空,将元素入栈
}else{
stack.push(inBound[in]);
in++;
}
//无入栈元素时,直接出栈栈顶元素,与出栈序列比较,若不同,false,否则继续
}else{
int tem = stack.pop();
if(tem == outBound[out]){
out++;
}else{
return false;
}
}
}
return true;
}