LightOJ - 1047 Neighbor House(DP)

题目大意：给你N个相邻的点，现在要求你将这些点染色(红，蓝，绿)，使得任意相邻的点的颜色不一样，且染色的费用达到最小

解题思路：用dp[i][j]表示前i个点都染色了，且第i个点染成j的颜色需要的最小费用

则dp[i][j] = min(dp[i][k]) + val[i][j]

#include <cstdio>
#include <algorithm>
#include <cstring>
using namespace std;
const int N = 30;

int mat
[3];
int dp
[3];
int n, cas = 1;

void init() {
scanf("%d", &n);
for (int i = 0; i < n; i++)
for (int j = 0; j < 3; j++)
scanf("%d", &mat[i][j]);
}

void solve() {
memset(dp, 0x3f, sizeof(dp));
dp[0][0] = mat[0][0];
dp[0][1] = mat[0][1];
dp[0][2] = mat[0][2];

for (int i = 1; i < n; i++)
for (int j = 0; j < 3; j++)
for (int k = 0; k < 3; k++)
if (j != k) dp[i][j] = min(dp[i][j], dp[i - 1][k] + mat[i][j]);
printf("Case %d: %d\n", cas++, min(min(dp[n - 1][0], dp[n - 1][1]), dp[n - 1][2]));
}

int main() {
int test;
scanf("%d", &test);
while (test--) {
init();
solve();
}
return 0;
}