Merge pull request doocs#68 from bluesword12350/master

008. String to Integer (atoi) (java)

Author: yanglbme

solution/008. String to Integer (atoi)/Solution.java

@@ -0,0 +1,30 @@
+class Solution {
+    public int myAtoi(String str) {
+        int len = str.length();
+        if (len == 0) return 0;
+        char[] cs = str.toCharArray();
+        int i = 0;
+        while (i < len && cs[i] == ' ') i++;
+        if (i==len) return 0;
+        char c1 = cs[i];
+        int sig = 1;
+        if ((c1 > '9' || c1 < '0')) {
+            if (c1 == '-') {
+                sig = -1;
+                i++;
+            } else if (c1 == '+') {
+                i++;
+            } else return 0;
+        }
+        long v = 0,sv = 0;
+        for (; i < len; i++) {
+            char c = cs[i];
+            if (c < '0' || c > '9') break;
+            v = v * 10 + (c - '0');
+            sv = v * sig;
+            if (sv > Integer.MAX_VALUE) return Integer.MAX_VALUE;
+            else if (sv < Integer.MIN_VALUE) return Integer.MIN_VALUE;
+        }
+        return (int) sv;
+    }
+}