From eb2426e4deb4b67bd4b61f173bb97519fdd65f56 Mon Sep 17 00:00:00 2001
From: unlockable <gaogao174561@outlook.com>
Date: Fri, 22 Aug 2025 00:10:06 +0800
Subject: [PATCH] add prob 7

---
 7-13.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 7-13.c

diff --git a/7-13.c b/7-13.c
new file mode 100644
index 0000000..51942cd
--- /dev/null
+++ b/7-13.c
@@ -0,0 +1,63 @@
+#include <stdio.h>
+#include <string.h>
+
+int romanToInt(char* s) {
+    int ans = 0;
+    int len = strlen(s);
+    for (int i = 0; i < len; ++i) {
+        char cur = s[i];
+        char peeknext;
+        if (i == len - 1) {
+            peeknext = ' ';
+        } else {
+            peeknext = s[i + 1];
+        }
+        switch (cur)
+        {
+        case 'I':
+            if (peeknext == 'V' || peeknext == 'X') {
+                ans -= 1;
+            } else {
+                ans += 1;
+            }
+            break;
+        
+        case 'V':
+            ans += 5;
+            break;
+        case 'X':
+            if (peeknext == 'L' || peeknext == 'C') {
+                ans -= 10;
+            } else {
+                ans += 10;
+            }
+            break;
+        case 'L':
+            ans += 50;
+            break;
+        case 'C':
+            if (peeknext == 'D' || peeknext == 'M') {
+                ans -= 100;
+            } else {
+                ans += 100;
+            }
+            break;
+        case 'D':
+            ans += 500;
+            break;
+        case 'M':
+            ans += 1000;
+            break;
+        
+        default:
+            break;
+        }
+    }
+    return ans;
+}
+
+int main() {
+    char s[] = "LVIII";
+    printf("%d\n", romanToInt(s));
+    return 0;
+}
\ No newline at end of file