finished cls04

src/cls04/a2.c

@@ -0,0 +1,43 @@
+#include <stdio.h>
+
+#include "reduce.h"
+#include "utils.h"
+
+int subFrac(int x[], int y[]) {
+    if (x[1] == 0 || y[1] == 0) {
+        return -1;
+    }
+
+    int l = lcm(x[1], y[1]);
+    int z[] = {
+        (x[0] * l)/x[1] - (y[0] * l)/y[1],
+        l
+    };
+
+    reduce(z);
+    formatNeg(z);
+
+    x[0] = z[0];
+    x[1] = z[1];
+
+    return 0;
+}
+
+int main(void) {
+    int x[2] = {0};
+    int y[2] = {0};
+
+    inputFrac(x);
+    inputFrac(y);
+
+    int ret = subFrac(x, y);
+
+    if (ret == 0) {
+        printFrac(x);
+        putchar('\n');
+    } else {
+        fprintf(stderr, "Error: detected zero div\n");
+    }
+
+    return 0;
+}