SRM 596 D2 L2：ColorfulRoad，dp

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题目：http://community.topcoder.com/stat?c=problem_statement&pm=12837

类似于弗洛伊德最短路径算法思想。

代码：

#include <algorithm>#include <iostream>#include <sstream>#include <string>#include <vector>#include <stack>#include <deque>#include <queue>#include <set>#include <map>#include <cstdio>#include <cstdlib>#include <cctype>#include <cmath>#include <cstring>#include <ctime>using namespace std;#define CHECKTIME() printf("%.2lf\n", (double)clock() / CLOCKS_PER_SEC)/*************** Program Begin **********************/int dp[20][20];class ColorfulRoad {public:int getMin(string road) {int res = 0;int n = road.size();vector <int> v;for (int i = 0; i < n; i++) {if (road[i] == 'R') {v.push_back(0);} else if (road[i] == 'G') {v.push_back(1);} else {v.push_back(2);}}memset(dp, -1, sizeof(dp));for (int len = 1; len <= n - 1; len++) {for (int i = 0; i <= n - len - 1; i++) {int & ans = dp[i][i+len];if ( (v[i] + 1) % 3 == v[i+len] ) {ans = len * len;}for (int j = i + 1; j < i + len; j++) {if (dp[i][j] == -1 || dp[j][i+len] == -1) {continue;}if (ans == -1) {ans = dp[i][j] + dp[j][i+len];}ans = min(ans, dp[i][j] + dp[j][i+len]);}}}res = dp[0][n-1];return res;}};/************** Program End ************************/

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