HDU 2084 数塔 （水DP）

题意：....

析：从下往上算即可，水DP。

代码如下：

#pragma comment(linker, "/STACK:1024000000,1024000000")
#include <cstdio>
#include <string>
#include <cstdlib>
#include <cmath>
#include <iostream>
#include <cstring>
#include <set>
#include <queue>
#include <algorithm>
#include <vector>
#include <map>
#include <cctype>
#include <stack>
using namespace std;

typedef long long LL;
typedef pair<int, int> P;
const int INF = 0x3f3f3f3f;
const double inf = 0x3f3f3f3f3f3f;
const LL LNF = 100000000000000000;
const double PI = acos(-1.0);
const double eps = 1e-8;
const int maxn = 1e2 + 5;
const int mod = 1e9 + 7;
const char *mark = "+-*";
const int dr[] = {-1, 0, 1, 0};
const int dc[] = {0, 1, 0, -1};
int n, m;
inline bool is_in(int r, int c){
    return r >= 0 && r < n && c >= 0 && c < m;
}
inline LL Max(LL a, LL b){  return a < b ? b : a; }
inline LL Min(LL a, LL b){  return a > b ? b : a; }
inline int Max(int a, int b){  return a < b ? b : a; }
inline int Min(int a, int b){  return a > b ? b : a; }
int a[maxn][maxn];
int d[maxn][maxn];

int main(){
    int T;  cin >> T;
    while(T--){
        memset(d, 0, sizeof(d));
        scanf("%d", &n);
        for(int i = 0; i < n; ++i)
            for(int j = 0; j <= i; ++j)
                scanf("%d", &a[i][j]);

        for(int i = 0; i < n; ++i) d[n-1][i] = a[n-1][i];

        for(int i = n-2; i >= 0; --i)
            for(int j = 0; j <= i; ++j)
                d[i][j] = Max(d[i+1][j], d[i+1][j+1]) + a[i][j];

        printf("%d
", d[0][0]);
    }

    return 0;
}