DP--数字三角形模型

摘花生

#include <iostream>
#include <cstring>
#include <algorithm>

using namespace std;

const int N = 1010;
int f[N][N], T, n, m, w[N][N];

int main() 
{
    scanf("%d", &T);
    
    while (T -- ) 
    {
        scanf("%d%d", &n, &m);
        
        for (int i = 1; i <= n; i ++ ) 
            for (int j = 1; j <= m; j ++ ) 
            {
                scanf("%d", &w[i][j]);
                f[i][j] = max(f[i - 1][j], f[i][j - 1]) + w[i][j];
            }
        printf("%d\n", f[n][m]);
    }
    
    
    return 0;
}

最低通行费

#include <iostream>
#include <cstring>
#include <algorithm>

using namespace std;

const int N = 110;
int f[N][N], n, w[N][N];

int main() 
{
    scanf("%d", &n);
    
    memset(f, 0x3f, sizeof f);
    for (int i = 1; i <= n; i ++ ) 
        for (int j = 1; j <= n; j ++ )
            scanf("%d", &w[i][j]);
    
    for (int i = 1; i <= n; i ++ ) 
        for (int j = 1; j <= n; j ++ ) 
            if (i == 1 && j == 1) f[i][j] = w[i][j];
            else f[i][j] = min(f[i - 1][j], f[i][j - 1]) + w[i][j];
    
    printf("%d\n", f[n][n]);
    
    return 0;
}

方格取数

#include <iostream>
#include <cstring>

using namespace std;

const int N = 15;
int f[N + N][N][N], n, w[N][N];

int main() 
{
    scanf("%d", &n);
    
    int a, b, c;
    while (scanf("%d%d%d", &a, &b, &c) && a || b) w[a][b] = c;
    
    for (int k = 1; k <= n + n; k ++ ) 
        for (int i1 = 1; i1 <= n; i1 ++ ) 
            for (int i2 = 1; i2 <= n; i2 ++ ) 
            {
                int j1 = k - i1, j2 = k - i2;
                if (j1 < 1 || j1 > n || j2 < 1 || j2 > n) continue ;
                
                int &x = f[k][i1][i2];
                int t = w[i1][j1];
                if (i1 != i2) t += w[i2][j2];
                
                x = max(x, f[k - 1][i1][i2 - 1] + t);
                x = max(x, f[k - 1][i1][i2] + t);
                x = max(x, f[k - 1][i1 - 1][i2] + t);
                x = max(x, f[k - 1][i1 - 1][i2 - 1] + t);
            }
    
    printf("%d\n", f[n + n][n][n]);
    
    return 0;
}

#include <iostream>
#include <cstring>

using namespace std;

const int N = 100;
int f[N][N][N], n, w[N][N], m;

int main() 
{
    scanf("%d%d", &n, &m);
    
    for (int i = 1; i <= n; i ++ ) 
        for (int j = 1; j <= m; j ++ ) 
            scanf("%d", &w[i][j]);
    
    for (int k = 1; k <= n + m; k ++ ) 
        for (int i = 1; i < k; i ++ ) 
            for (int j = 1; j < k; j ++ ) 
            {
                int &x = f[k][i][j];
                int t = w[i][k - i];
                if (i != j) t += w[j][k - j];
                
                x = max(x, f[k - 1][i][j - 1] + t);
                x = max(x, f[k - 1][i][j] + t);
                x = max(x, f[k - 1][i - 1][j] + t);
                x = max(x, f[k - 1][i - 1][j - 1] + t);
            }
    
    printf("%d\n", f[n + m][n][n]);
    
    return 0;
}