100!

2023210/main.cpp

@@ -15,40 +15,40 @@ int dim_sizes[32] = {0};
 
 // int precalc[2][1048576] = {0};
 
-int tensor_pos(int num, int dim) {
+inline int tensor_pos(int num, int dim) {
     return k * num + dim;
 }
 
-int setm(int i, int j, int num) {
+inline int setm(int i, int j, int num) {
     if (j <= i) {
         return 0;
     }
 
-    return m[(2 * n - i + 1) * i / 2 + j - i].min_multiply_times = num;
+    return m[i * n + j].min_multiply_times = num;
 }
 
-int getm(int i, int j) {
+inline int getm(int i, int j) {
     if (j <= i) {
         return 0;
     }
 
-    return m[(2 * n - i + 1) * i / 2 + j - i].min_multiply_times;
+    return m[i * n + j].min_multiply_times;
 }
 
-int setmdim(int i, int j, int d) {
+inline int setmdim(int i, int j, int d) {
     if (j < i) {
         return 0;
     }
 
-    return m[(2 * n - i + 1) * i / 2 + j - i].dim_status = d;
+    return m[i * n + j].dim_status = d;
 }
 
-int getmdim(int i, int j) {
+inline int getmdim(int i, int j) {
     if (j < i) {
         return 0;
     }
 
-    return m[(2 * n - i + 1) * i / 2 + j - i].dim_status;
+    return m[i * n + j].dim_status;
 }
 
 int find_min(int start, int end) {
@@ -85,6 +85,40 @@ int find_min(int start, int end) {
     return min;
 }
 
+int clac_min() {
+    for (int i = 0; i < n; i++) {
+        setm(i, i, 0);
+    }
+
+    for (int length = 1; length <= n; length++) {
+        for (int start = 0; start <= n - length; start++) {
+            int min = 2147483647;
+            int needed_multiply_by_d = 1;
+            int dim_status = getmdim(start, start + length);
+
+            // prepare the dims
+            for (int i = 0; i < k - 2; i++) {
+                if ((dim_status >> i) & 1) {
+                    needed_multiply_by_d *= dim_sizes[i];
+                }
+            }
+
+            int matrix_partial_needed = tensors[tensor_pos(start, k - 2)] *
+                                        tensors[tensor_pos(start + length, k - 1)] * needed_multiply_by_d;
+
+            for (int split = 0; split < length; split++) {
+                int total_needed = matrix_partial_needed * tensors[tensor_pos(start + split, k - 1)] + getm(start, start + split) + getm(start + split + 1, start + length);
+                if (total_needed < min) {
+                    min = total_needed;
+                }
+            }
+            setm(start, start + length, min);
+        }
+    }
+
+    return 0;
+}
+
 void preparedim(int length) {
     if (length == 1) {
         for (int i = 0; i < n; i++) {
@@ -108,7 +142,8 @@ void preparedim(int length) {
 int main() {
     scanf("%d %d", &n, &k);
     tensors = new unsigned short[n * k];
-    m = new CalcResult[(n + 1) * n / 2];
+    // m = new CalcResult[(n + 1) * n / 2];
+    m = new CalcResult[n * n];
 
     for (int i = 0; i < 32; i++) {
         dim_sizes[i] = 1;
@@ -137,7 +172,10 @@ int main() {
 
     preparedim(n);
 
-    printf("%d\n", find_min(0, n - 1));
+    // printf("%d\n", find_min(0, n - 1));
+
+    clac_min();
+    printf("%d\n", getm(0, n - 1));
 
     return 0;
 }