a1 - 1

a1/program.c

@@ -0,0 +1,76 @@
+#include <stdio.h>
+#include <string.h>
+
+#define MAX_LEN 100
+
+int isOpening(char c){
+	if (c == '(' || c == '[' || c == '{' || c == '<') return 1
+}
+
+int isClosing(char c){
+	if (c == ')' || c == ']' || c == '}' || c == '>') return 1
+}
+
+char expectedCLosing(char c){
+	switch (c) {
+		case '(': return ')';
+		case '[': return ']';
+		case '{': return '}';
+		case '<': return '>';
+		default: return '?';
+	}
+}
+
+char expectedOpening(char c){
+	switch (c) {
+		case ')': return '(';
+		case ']': return '[';
+		case '}': return '{';
+		case '>': return '<';
+	}
+}
+
+
+int main(){
+	char code[MAX_LEN + 1];
+	char stack[MAX_LEN];
+	int top = -1;
+
+	if (!fgets(code, sizeof(code), stdin)){
+		printf("Input error\n");
+		return 1;
+	}
+
+	code[strcspn(code, "\n")] = '\0';
+
+	printf("Read: %s\n", code);
+
+	int len = strlen(code);
+	for (int i = 0; i < len; i++){
+		c = code[i];
+
+		if (isOpening(c)){
+			if (top < MAX_LEN - 1){
+				stack[++top] = c;
+			}
+		}
+		else if (isClosing(c)){
+			if (top < 0){
+				printf("Unexpected closing bracket %c in %d\n", c, i+1);
+				return 0;
+			}
+			char last = stack[top--];
+			if (expectedClosing(last) != c){
+				printf("Crossed bracket %c in %d, expected %c\n", c, i+1, expectedClosing(last));
+				return 0;
+			}
+		}
+	}
+	if (top >= 0){
+		printf("Unclosed bracket %c in %d\n", stack[top], len);
+	} else {
+		printf("All brackets OK\n");
+	}
+
+	return 0;
+}