Первая лаба

myatoi.c

@@ -0,0 +1,51 @@
+#include <stdio.h>
+#include <ctype.h>
+#include <limits.h>
+
+int myatoi(char *instr) {
+	if (instr == NULL) {
+		return 0;
+	}
+
+	while (isspace((unsigned char)*instr)) {
+		instr++;
+	}
+
+	int sign = 1;
+	if (*instr == '+') {
+		instr++;
+	} else if (*instr == '-') {
+		sign = -1;
+		instr++;
+	}
+
+	long result = 0;
+	while (*instr >= '0' && *instr <= '9') {
+		int digit = *instr - '0';
+
+		if (sign > 0) {
+			if (result > (LONG_MAX - digit) / 10) {
+				return INT_MAX;
+			}
+		} else {
+			if (-result < (LONG_MIN + digit) / 10) {
+				return INT_MIN;
+			}
+		}
+
+		result = result * 10 + digit;
+		instr++;
+	}
+
+	return (int)(result * sign);
+}
+
+int main() {
+printf("myatoi(\"1\") = %d\n", myatoi("1"));
+    printf("myatoi(\"42\") = %d\n", myatoi("42"));
+    printf("myatoi(\"-105\") = %d\n", myatoi("-105"));
+    printf("myatoi(\"   -12abc34\") = %d\n", myatoi("   -12abc34"));
+    printf("myatoi(\"9999999999999\") = %d (overflow)\n", myatoi("9999999999999"));
+
+    return 0;
+}