add: graphs et rushs

2 files changed, 69 insertions, 0 deletions

diff --git a/rushs/evalexpr/my_atoi/my_atoi.c b/rushs/evalexpr/my_atoi/my_atoi.c
new file mode 100644
index 0000000..ca185a5
--- /dev/null
+++ b/rushs/evalexpr/my_atoi/my_atoi.c
@@ -0,0 +1,61 @@
+#include "my_atoi.h"
+
+int my_atoi(const char *str)
+{
+    int res = 0;
+
+    // str error check
+    if (str == NULL || *str == '0')
+    {
+        return 0;
+    }
+
+    // trim whitespaces
+    for (; *str && *str == ' '; str++)
+    {
+        continue;
+    }
+
+    // move to end of str
+    size_t l;
+    for (l = 0; str[l]; l++)
+    {
+        continue;
+    }
+    l--;
+
+    // prepare for calculations
+    int factor = 1;
+
+    // actual conversion of up to the second element of str (potential sign)
+    for (; l > 0; l--)
+    {
+        char val = str[l];
+        if (val < '0' || val > '9')
+        {
+            return 0;
+        }
+        val -= '0';
+        res += val * factor;
+
+        factor *= 10;
+    }
+
+    // l should be 0 by now
+    if (str[l] == '-')
+    {
+        return -res;
+    }
+    else if (str[l] != '+')
+    {
+        int val = str[l];
+        if (val < '0' || val > '9')
+        {
+            return 0;
+        }
+        val -= '0';
+        return res + val * factor;
+    }
+
+    return res;
+}
diff --git a/rushs/evalexpr/my_atoi/my_atoi.h b/rushs/evalexpr/my_atoi/my_atoi.h
new file mode 100644
index 0000000..b520d09
--- /dev/null
+++ b/rushs/evalexpr/my_atoi/my_atoi.h
@@ -0,0 +1,8 @@
+#ifndef MY_ATOI_H
+#define MY_ATOI_H
+
+#include <stddef.h>
+
+int my_atoi(const char *str);
+
+#endif /* ! MY_ATOI_H */