#include <stdio.h> #define MIN(a,b) ((a) < (b) ? a : b) #define INF 0x7fffffffffffffffLL #define LL (long long) typedef unsigned char byte; typedef struct SNode SNode; struct SNode{ int curr; int fleft; int fright; int begin; int end; byte sign; }; int a[1000002]; char str[1000002]; int pos[1000002]; SNode val[1000002]; byte visi[1000002]; long long ans[1000002]; int tree[2400002],N; void setVal(int n, int m); void setInterval(int begin, int end); void solve(int n, int m); long long getAns(int x, int a, int n, int m); int main(void) { int n, m, i; scanf("%d",&n); for(i = 0; i < n; i++){ scanf("%d",&a[i]); } scanf("%d %s",&m,str); setVal(n,m); solve(n,m); return 0; } void setInterval(int begin, int end) { int lprev = MIN(val[begin].curr, 0); int rprev = 0; int i = begin, j = end, iter = end - begin + 1; while( iter-- ){ val[i].fleft = lprev = MIN(val[i].curr, lprev); rprev = ( val[j].sign ) ? MIN(rprev + 1, 0) : rprev - 1; val[j].fright = rprev; val[i].begin = begin; val[i].end = end; ++i; --j; } } void setVal(int n, int m) { int iter = 0; int i = 0, j = 0, curr = 0, b = 0, x; for(x=N=1; m>N; x++,N<<=1); while(iter < m){ x = ( i + LL(j)*n ) % m; if( visi[x] ){ setInterval(b,iter-1); b = iter; ++i; j = curr = 0; x = (i + LL(j*n) ) % m; } visi[x] = 1; pos[x] = iter; val[iter].sign = (str[x] == 'W'); curr += (val[iter].sign) ? 1 : -1; val[iter].curr = curr; tree[iter+N] = curr; ++j; ++iter; } setInterval(b,iter-1); for(i=N>>1,j=N; i; i>>=1,j>>=1){ for(x = i; x < j; x++){ tree[x] = MIN(tree[x<<1],tree[(x<<1)+1]); } } } void solve(int n, int m) { int i; long long res = INF; for(i = 0; i < n; i++){ ans[i] = getAns(i, a[i], n, m); res = MIN(res, ans[i]); } if(res == INF) printf("-1\n"); else printf("%lld\n",res); } int query(int f, int s) { f += N; s += N; int res = MIN(tree[f],tree[s]); while(f>>1 != s>>1) { if(~f&1) res = MIN(res,tree[f+1]); if(s&1) res = MIN(res,tree[s-1]); f >>= 1; s >>= 1; } return res; } int binarySearchR(SNode *t, int l, int r, int a) { int end = r, p = l; int s, v; while(l < r){ s = (l + r)>>1; if(s == end) v = t[p].fright; else v = query(p,s) - tree[p-1+N]; if(a == v) r = s; else if(a > v) r = s - 1; else l = s + 1; } return l; } int binarySearchL(SNode *t, int l, int r, int a, int bias) { int s; while(l < r){ s = (l + r)>>1; if(a == bias + t[s].fleft) r = s; else if(a > bias + t[s].fleft) r = s - 1; else l = s + 1; } return l; } long long NWD(long long a, long long b){ long long c; while(b){ c = a%b; a = b; b = c; } return a; } long long NWW(long long a, long long b){ return a/NWD(a,b)*b; } long long getAns(int i, int a, int n, int m) { int x = i%m; int p = pos[x]; int begin = val[p].begin; int end = val[p].end; int ds = val[end].curr; int ms = val[p].fright; if(p > begin) ms = MIN(ms, val[end].curr - val[p-1].curr + val[p-1].fleft); long long res = 0; int ix; if(ms >= 0) return INF; if(ds >= 0){ if(a + ms > 0) return INF; } else if(a > -ms){ int k = (a + ms - ds - 1)/(-ds); res += LL(k)*NWW(n,m); a -= k*(-ds); } if(p == begin){ ix = binarySearchL(val, begin, end, -a, 0); res += LL(ix - p)*n; } else if(val[p].fright <= -a){ ix = binarySearchR(val, p, end, -a); res += LL(ix - p)*n; } else{ ix = binarySearchL(val, begin, p-1, -a, val[end].curr - val[p-1].curr); res += LL(end - p + 1 + ix - begin)*n; } return res + i + 1; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 | #include <stdio.h> #define MIN(a,b) ((a) < (b) ? a : b) #define INF 0x7fffffffffffffffLL #define LL (long long) typedef unsigned char byte; typedef struct SNode SNode; struct SNode{ int curr; int fleft; int fright; int begin; int end; byte sign; }; int a[1000002]; char str[1000002]; int pos[1000002]; SNode val[1000002]; byte visi[1000002]; long long ans[1000002]; int tree[2400002],N; void setVal(int n, int m); void setInterval(int begin, int end); void solve(int n, int m); long long getAns(int x, int a, int n, int m); int main(void) { int n, m, i; scanf("%d",&n); for(i = 0; i < n; i++){ scanf("%d",&a[i]); } scanf("%d %s",&m,str); setVal(n,m); solve(n,m); return 0; } void setInterval(int begin, int end) { int lprev = MIN(val[begin].curr, 0); int rprev = 0; int i = begin, j = end, iter = end - begin + 1; while( iter-- ){ val[i].fleft = lprev = MIN(val[i].curr, lprev); rprev = ( val[j].sign ) ? MIN(rprev + 1, 0) : rprev - 1; val[j].fright = rprev; val[i].begin = begin; val[i].end = end; ++i; --j; } } void setVal(int n, int m) { int iter = 0; int i = 0, j = 0, curr = 0, b = 0, x; for(x=N=1; m>N; x++,N<<=1); while(iter < m){ x = ( i + LL(j)*n ) % m; if( visi[x] ){ setInterval(b,iter-1); b = iter; ++i; j = curr = 0; x = (i + LL(j*n) ) % m; } visi[x] = 1; pos[x] = iter; val[iter].sign = (str[x] == 'W'); curr += (val[iter].sign) ? 1 : -1; val[iter].curr = curr; tree[iter+N] = curr; ++j; ++iter; } setInterval(b,iter-1); for(i=N>>1,j=N; i; i>>=1,j>>=1){ for(x = i; x < j; x++){ tree[x] = MIN(tree[x<<1],tree[(x<<1)+1]); } } } void solve(int n, int m) { int i; long long res = INF; for(i = 0; i < n; i++){ ans[i] = getAns(i, a[i], n, m); res = MIN(res, ans[i]); } if(res == INF) printf("-1\n"); else printf("%lld\n",res); } int query(int f, int s) { f += N; s += N; int res = MIN(tree[f],tree[s]); while(f>>1 != s>>1) { if(~f&1) res = MIN(res,tree[f+1]); if(s&1) res = MIN(res,tree[s-1]); f >>= 1; s >>= 1; } return res; } int binarySearchR(SNode *t, int l, int r, int a) { int end = r, p = l; int s, v; while(l < r){ s = (l + r)>>1; if(s == end) v = t[p].fright; else v = query(p,s) - tree[p-1+N]; if(a == v) r = s; else if(a > v) r = s - 1; else l = s + 1; } return l; } int binarySearchL(SNode *t, int l, int r, int a, int bias) { int s; while(l < r){ s = (l + r)>>1; if(a == bias + t[s].fleft) r = s; else if(a > bias + t[s].fleft) r = s - 1; else l = s + 1; } return l; } long long NWD(long long a, long long b){ long long c; while(b){ c = a%b; a = b; b = c; } return a; } long long NWW(long long a, long long b){ return a/NWD(a,b)*b; } long long getAns(int i, int a, int n, int m) { int x = i%m; int p = pos[x]; int begin = val[p].begin; int end = val[p].end; int ds = val[end].curr; int ms = val[p].fright; if(p > begin) ms = MIN(ms, val[end].curr - val[p-1].curr + val[p-1].fleft); long long res = 0; int ix; if(ms >= 0) return INF; if(ds >= 0){ if(a + ms > 0) return INF; } else if(a > -ms){ int k = (a + ms - ds - 1)/(-ds); res += LL(k)*NWW(n,m); a -= k*(-ds); } if(p == begin){ ix = binarySearchL(val, begin, end, -a, 0); res += LL(ix - p)*n; } else if(val[p].fright <= -a){ ix = binarySearchR(val, p, end, -a); res += LL(ix - p)*n; } else{ ix = binarySearchL(val, begin, p-1, -a, val[end].curr - val[p-1].curr); res += LL(end - p + 1 + ix - begin)*n; } return res + i + 1; } |