P1015 回文数

R39762388

problem/P1015/P1015.cpp

@@ -0,0 +1,62 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+bool check(string s) {
+    string r = s;
+    reverse(r.begin(), r.end());
+    return r == s;
+}
+
+string add(string b, int k) {
+    string a        = b;
+    char   sixt[20] = "0123456789ABCDEF";
+    reverse(a.begin(), a.end());
+    int    numa[105], numb[105], numc[105];
+    int    len = a.length(), lenc = 1;
+    string ans;
+    for (int i = 0; i < len; i++) {
+        if (isdigit(a[i])) {
+            numa[len - i] = a[i] - '0';
+        }
+        else {
+            numa[len - i] = a[i] - 'A' + 10;
+        }
+        if (isdigit(b[i])) {
+            numb[len - i] = b[i] - '0';
+        }
+        else {
+            numb[len - i] = b[i] - 'A' + 10;
+        }
+    }
+    int x = 0;
+    while (lenc <= len) {
+        numc[lenc] = numa[lenc] + numb[lenc] + x;
+        x          = numc[lenc] / k;
+        numc[lenc] %= k;
+        lenc++;
+    }
+    numc[lenc] = x;
+    while (numc[lenc] == 0) {
+        lenc--;
+    }
+    for (int i = lenc; i >= 1; i--) {
+        ans += sixt[numc[i]];
+    }
+    return ans;
+}
+
+int main() {
+    int    n;
+    string m;
+    cin >> n >> m;
+    for (int i = 0; i <= 30; i++) {
+        if (check(m)) {
+            cout << "STEP=" << i << endl;
+            return 0;
+        }
+        m = add(m, n);
+    }
+    cout << "Impossible!" << endl;
+    return 0;
+}