'commit'

TangDou/LuoGuBook/P1363_Prepare.cpp

@@ -0,0 +1,23 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+/**
+ 功能：正数+负数取模
+ n=3为例
+ MOD就是一直0,1,2,0,1,2这样的向下走，不会乱了规矩
+ MOD     0    1     2     0     1     2     0    1    2
+         @    @     @     @     @     @     @    @    @
+ a      -3   -2    -1     0     1     2     3    4    5
+ */
+int MOD(int a, int b) {
+    return (a % b + b) % b; //配合数组下标从0开始合适
+}
+
+int main() {
+    int n = 5;
+    for (int a = -4; a <= 2; a++) {
+        cout << "a=" << a << " MOD=" << MOD(a, n) << endl;
+    }
+    return 0;
+}