PAT 顶级 1026 String of Colorful Beads (35分)（尺取法）

题目链接：

1026 String of Colorful Beads

思路：

采用尺取法的思想，每次推动首尾，寻找最长、价值最大的区间即可；

代码：

#include<bits/stdc++.h>

using namespace std;

const int maxn = 12345;
int n, val[maxn], type[maxn];
bool vst[maxn];

int main(){
//	freopen("Sakura.txt", "r", stdin);
	scanf("%d", &n);
	for(int i = 1; i <= n; i++) scanf("%d", val + i);
	for(int i = 0; i < n; i++) scanf("%d", type + i);
	int lf, rt, len = 0, v = 0;
	int p = 0, q = 0, nowv = 0;
	while(true){
		while(vst[type[q]] == false && q < n) vst[type[q]] = true, nowv += val[type[q]], q++;
//		cerr<< p << ' ' << q << '
';
		int nowlen = q - p;
		if(nowlen > len || (nowlen == len && nowv > v)){
			lf = p, rt = q - 1, len = nowlen, v = nowv;
		}
		if(q >= n) break;
		while(vst[type[p]] = false, nowv -= val[type[p]], type[p++] != type[q]);
	}
	printf("%d %d %d
", v, lf, rt);
	return 0;
}