210508_TIL

백준 알고리즘 10773번 : 제로

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
	int k;
	int num;
	int* stack;
	int idx = 0;

	scanf("%d", &k);
	stack = (int*)malloc(sizeof(int) * k);
	for (int i = 0; i < k; i++)
	{
		scanf("%d", &num);
		if (num == 0)
			idx--;
		else
			stack[idx++] = num;
	}
	num = 0;
	for (int i = 0; i < idx; i++)
		num += stack[i];
	free(stack);
	printf("%d", num);
}

백준 알고리즘 9012번 : 괄호

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
	int t;
	int idx = 0;

	scanf("%d", &t);
	int* arr = (int*)malloc(sizeof(int) * t);
	for (int i = 0; i < t; i++)
	{
		char str[51] = { 0, };
		scanf("%s", str);
		int idx = 0;
		for (int j = 0; str[j]; j++)
		{
			if (str[j] == '(')
				idx++;
			else if (str[j] == ')')
				idx--;
			if (idx < 0)
				break;
		}
		if (idx == 0)
			arr[i] = 1;
		else
			arr[i] = 0;
	}
	for (int i = 0; i < t; i++)
	{
		if (arr[i] == 1)
			printf("YES");
		else
			printf("NO");
		if (i != t - 1)
			printf("\n");
	}
    free(arr);
	return (0);
}

백준 알고리즘 18258번 : 큐 2

#include <stdio.h>
#include <string.h>

int queue[2000001];
int front = 0;
int rear = -1;

void push(int x)
{
	queue[++rear] = x;
}

void pop()
{
	if (rear - front + 1 == 0)
		printf("-1\n");
	else
		printf("%d\n", queue[front++]);
}

void empty()
{
	if (rear - front + 1 != 0)
		printf("0\n");
	else
		printf("1\n");
}

int main(void)
{
	int n, t, x;
	char order[6];

	scanf("%d", &n);
	for (t = 0; t < n; t++)
	{
		scanf("%s", order);
		if (!strcmp(order, "push"))
		{
			scanf("%d", &x);
			push(x);
		}
		else if (!strcmp(order, "pop"))
			pop();
		else if (!strcmp(order, "size"))
			printf("%d\n", rear - front + 1);
		else if (!strcmp(order, "empty"))
			empty();
		else if (!strcmp(order, "front"))
		{
			if (rear - front + 1 == 0)
				printf("-1\n");
			else
				printf("%d\n", queue[front]);
		}
		else if (!strcmp(order, "back"))
		{
			if (rear - front + 1 == 0)
				printf("-1\n");
			else
				printf("%d\n", queue[rear]);
		}
		for (int j = 0; j < 6; j++)
			order[j] = 0;
	}
	return 0;
}