ch 5e02 线性dp

偷奸耍滑之偷工减料

#include <cstdio>
#include <iostream>
#include <iomanip>
#include <string>
#include <cstdlib>
#include <cstring>
#include <queue>
#include <set>
#include <vector>
#include <map>
#include <algorithm>
#include <cmath>
#include <stack>

#define INF 0x3f3f3f3f
#define IMAX 2147483646
#define LINF 0x3f3f3f3f3f3f3f3f
#define ll long long
#define ull unsigned long long
#define uint unsigned int

using namespace::std;

int n, m, a[111][111];
int f[111][111], beg, end, temp;

int main() {
	scanf("%d%d", &n, &m);
	for (int i = 1; i <= n; i++)
		for (int j = 1; j <= m; j++)
			scanf("%d", &a[i][j]);
	memset(f, -INF, sizeof(f));
	for (int j = 1; j <= m; j++)f[1][j] = max(f[1][j - 1], a[1][j]);
	for (int i = 2; i <= n; i++) {
		f[i][i] = f[i - 1][i - 1] + a[i][i];
		for (int j = i + 1; j <= m; j++) 
			f[i][j] = max(f[i][j - 1], f[i - 1][j - 1] + a[i][j]);
	}
	printf("%d\n", f[n][m]);

	return 0;
}