矩阵链乘法

最新推荐文章于 2025-05-26 16:25:16 发布

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#include <stdio.h>
#define N 110
#define INF 0x3f3f3f3f

int main() {
    int t, n, i, j, k, l, q;
    int m[N][N], p[N];

    scanf("%d", &t);
    while (t--) {
        scanf("%d", &n);
        for (i = 0; i <= n; i++) {
            scanf("%d", &p[i]);
            m[i][i] = 0;
        }
        for (l = 2; l <= n; l++) {
            for (i = 1; i <= n - l + 1; i++) {
                j = i + l - 1;
                m[i][j] = INF;
                for (k = i; k < j; k++) {
                    q = m[i][k] + m[k + 1][j] + p[i - 1] * p[k] * p[j];
                    if (q < m[i][j]) 
                        m[i][j] = q;
                }
            }
        }
        printf("%d\n", m[1][n]);
    }
    return 0;
}

/**

MEMOIZED-MATRIX-CHAIN

**/

#include <stdio.h>
#include <string.h>
#define N 110
#define INF 0x3f3f3f3f

int m[N][N], p[N];

int fun(int i, int j) {
	if (m[i][j] < INF)
		return m[i][j];
	int k, q;

	for (k = i; k < j; k++) {
		q = fun(i, k) + fun(k + 1, j) + p[i - 1] * p[k] * p[j];
		if (q < m[i][j])
			m[i][j] = q;
	}
	return m[i][j];
}

int main() {
	int t, n, i;

	scanf("%d", &t);
	while (t--) {
		memset(m, INF, sizeof(m));
		scanf("%d", &n);
		for (i = 0; i <= n; i++) {
			scanf("%d", &p[i]);
			m[i][i] = 0;
		}
		fun(1, n);
		printf("%d\n", m[1][n]);
	}
	return 0;
}