USACO Section 1.5: Number Triangles

 1 /*

 2 ID: leetcod3

 3 PROG: numtri

 4 LANG: C++

 5 */

 6 #include <iostream>

 7 #include <fstream>

 8 #include <string>

 9 #include <map>

10 #include <vector>

11 #include <set>

12 #include <algorithm>

13 #include <queue>

14 #include <cmath>

15 #include <list>

16 #include <cstring>

17 #include <cstdlib>

18 #include <limits>

19 #include <stack>

20 

21 using namespace std;

22 

23 ofstream fout ("numtri.out");

24 ifstream fin ("numtri.in");

25 

26 int main()

27 {

28     int R;

29     fin >> R;

30     vector<vector<int> > num;

31     for (int i = 1; i <= R; i++) {

32         vector<int> input(i);

33         for (int j = 0; j < i; j++) fin >> input[j];

34         num.push_back(input);

35     }

36     for (int i = 1; i < R; i++) {

37         for (int j = 0; j < num[i].size(); j++) {

38             if (j == 0) num[i][j] += num[i-1][j];

39             else if (j == num[i].size()-1) num[i][j] += num[i-1][num[i-1].size()-1];

40             else num[i][j] += max(num[i-1][j-1], num[i-1][j]);

41         }

42     }

43     int ans = 0;

44     for (int i = 0; i < R; i++) ans = max(ans, num[R-1][i]);

45     fout << ans << endl;

46     return 0;

47 }