题目大意：
<??http://www.2cto.com/kf/ware/vc/" target="_blank" class="keylink">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"brush:java;">#include
#include
#include
#include
#define MAX 500010 using namespace std; #define min(a,b) ((a) < (b) ? (a):(b)) char s[MAX]; int len; int val[MAX],sa[MAX]; int height[MAX],rank[MAX]; inline bool Same(int x,int y,int l) { return val[x] == val[y] && ((x + l >= len && y + l >= len) || (x + l < len && y + l < len && val[x + l] == val[y + l])); } void GetSuffixArray() { static int _val[MAX],q[MAX],cnt[MAX],lim = 256; for(int i = 0; i < len; ++i) ++cnt[val[i] = s[i]]; for(int i = 1; i < lim; ++i) cnt[i] += cnt[i - 1]; for(int i = len - 1; ~i; --i) sa[--cnt[val[i]]] = i; for(int d = 1;; ++d) { int top = 0,l = 1 << (d - 1); for(int i = 0; i < len; ++i) if(sa[i] + l >= len) q[top++] = sa[i]; for(int i = 0; i < len; ++i) if(sa[i] >= l) q[top++] = sa[i] - l; for(int i = 0; i < lim; ++i) cnt[i] = 0; for(int i = 0; i < len; ++i) ++cnt[val[q[i]]]; for(int i = 1; i < lim; ++i) cnt[i] += cnt[i - 1]; for(int i = len - 1; ~i; --i) sa[--cnt[val[q[i]]]] = q[i]; lim = 0; for(int i = 0,j; i < len; ++lim) { for(j = i; j < len - 1 && Same(sa[j],sa[j + 1],l); ++j); for(; i <= j; ++i) _val[sa[i]] = lim; } for(int i = 0; i < len; ++i) val[i] = _val[i]; if(lim == len) break; } return ; } void GetHeight() { for(int i = 0; i < len; ++i) rank[sa[i]] = i; for(int i = 0,k = 0; i < len; ++i) { if(!rank[i]) continue; if(k) --k; int j = sa[rank[i] - 1]; while(s[i + k] == s[j + k]) ++k; height[rank[i]] = k; } } int l[MAX],r[MAX]; int stack[MAX],top; int main() { scanf("%s",s); len = strlen(s); GetSuffixArray(); GetHeight(); long long ans = (long long)(len + 1) * len * (len - 1) >> 1; for(int i = 1; i < len; ++i) { while(top && height[stack[top]] > height[i]) --top; if(!top) l[i] = 0; else l[i] = stack[top]; stack[++top] = i; } top = 0; for(int i = len - 1; i; --i) { while(top && height[stack[top]] >= height[i]) --top; if(!top) r[i] = len; else r[i] = stack[top]; stack[++top] = i; } for(int i = 1; i < len; ++i) ans -= (long long)(i - l[i]) * (r[i] - i) * height[i] * 2; printf("%lld\n",ans); return 0; }