http://projecteuler.net/problem=18
動的計画法。
1 #include <iostream>
2
3 using namespace std;
4
5 int data[15][15] = {
6 {75},
7 {95, 64},
8 {17, 47, 82},
9 {18, 35, 87, 10},
10 {20, 4, 82, 47, 65},
11 {19, 1, 23, 75, 3, 34},
12 {88, 2, 77, 73, 7, 63, 67},
13 {99, 65, 4, 28, 6, 16, 70, 92},
14 {41, 41, 26, 56, 83, 40, 80, 70, 33},
15 {41, 48, 72, 33, 47, 32, 37, 16, 94, 29},
16 {53, 71, 44, 65, 25, 43, 91, 52, 97, 51, 14},
17 {70, 11, 33, 28, 77, 73, 17, 78, 39, 68, 17, 57},
18 {91, 71, 52, 38, 17, 14, 91, 43, 58, 50, 27, 29, 48},
19 {63, 66, 4, 68, 89, 53, 67, 30, 73, 16, 69, 87, 40, 31},
20 {4, 62, 98, 27, 23, 9, 70, 98, 73, 93, 38, 53, 60, 4, 23},
21 };
22 int dp[15][15];
23
24 void debug() {
25 for (int i = 0; i < 15; i++) {
26 for (int j = 0; j <= i; j++) {
27 cout << dp[i][j] << ' ';
28 }
29 cout << endl;
30 }
31 }
32
33 int main() {
34 dp[0][0] = data[0][0];
35 for (int i = 1; i < 15; i++) {
36 dp[i][0] = dp[i-1][0] + data[i][0];
37 for (int j = 1; j < i; j++) {
38 dp[i][j] = max(dp[i-1][j-1], dp[i-1][j]) + data[i][j];
39 }
40 dp[i][i] = dp[i-1][i-1] + data[i][i];
41 }
42 int ans = 0;
43 for (int i = 0; i < 15; i++) {
44 ans = max(ans, dp[14][i]);
45 }
46 cout << ans << endl;
47 return 0;
48 }