Divide tow integers

Signed-off-by: begeekmyfriend <[email protected]>

029_divide_two_integers/Makefile

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+all:
+	gcc -O2 -o test divide.c

029_divide_two_integers/divide.c

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+#include <stdio.h>
+#include <stdlib.h>
+#include <limits.h>
+
+int divide(int dividend, int divisor) {
+    int sign = (float)dividend / divisor > 0 ? 1 : -1;
+    unsigned int dvd = dividend > 0 ? dividend : -dividend;
+    unsigned int dvs = divisor > 0 ? divisor : -divisor;
+
+    unsigned int bit_num[32];
+    unsigned int i = 0;
+    long long d = dvs;
+    bit_num[i] = d;
+    while (d <= dvd) {
+        bit_num[++i] = d = d << 1;
+    }
+    i--;
+
+    unsigned int result = 0;
+    while (dvd >= dvs) {
+        if (dvd >= bit_num[i]) {
+            dvd -= bit_num[i];
+            result += (1<<i);
+        } else {
+            i--;
+        }
+    }
+
+    //becasue need to return `int`, so we need to check it is overflowed or not.
+    if (result > INT_MAX && sign > 0) {
+        return INT_MAX;
+    }
+    return (int) result * sign;
+}
+
+int main(int argc, char **argv)
+{
+    if (argc != 3) {
+        fprintf(stderr, "Usage: ./test dividend divisor\n");
+        exit(-1);
+    }
+    printf("%d\n", divide(atoi(argv[1]), atoi(argv[2])));
+    return 0;
+}